JPH0645747A - Reflow device - Google Patents

Abstract

PURPOSE:To make it possible to prevent a substrate from being deformed due to the heat of heaters, to prevent the substrate from being warped and to prevent the substrate front falling front a converyor while the substrate is transferred in a heating chamber. CONSTITUTION:A conveyor 11, which is provided in a heating chamber 1, is constituted of one pair of left and right guide rails 13 and 14 for guiding both side end parts of a substrate S, pressing means 15 for pressing both side end parts of the substrate S to the guide rails 13 and 14 from over and a transfer means 17 for transferring the substrate S in such a way that the substrate S is made to slide on the guide rails 13 and 14. Accordingly, the substrate S is pressed to the guide rails 13 and 14 by the pressing means 15, whereby the thermal deformation of the substrate S and a fall of the substrate S from the conveyor 11 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflow apparatus, and more specifically, while a substrate is being conveyed in a heating chamber, the substrate is deformed by the heat of the heater, and the substrate warps or drops from a conveyor. The present invention relates to a reflow device that can prevent the occurrence of heat.

[0002]

2. Description of the Related Art After mounting a chip on a substrate by a chip mounter or the like, the substrate is sent to a heating chamber of a reflow machine,
The electrodes of the chip are soldered to the electrodes of the substrate by heating and melting the cream solder and then cooling and solidifying it. Next, a conventional reflow apparatus will be described with reference to FIG.

FIG. 5 is a sectional view of the reflow apparatus. Inside the heating chamber 1, a substrate S on which a chip P is mounted is introduced 2
A conveyer 4 is provided to convey from the outlet to the outlet 3, and a heater 5 and a fan 6 are provided above the conveyer 4. Reference numeral 9 is a drive motor for the conveyor 4, and 29 is a drive motor for the fan 6. The interior of the heating chamber 1 is divided into a preheating zone T1, a soaking zone T2, and a reflow zone T3 by two partition walls 30, and a cooling chamber 10 is provided at the rear of the heating chamber 1. The conveyor 4 is shown in FIG.
As shown in FIG. 5, it is composed of a pair of left and right chains 7, and attachments 8 are provided at regular intervals on the chains 7, and both end portions of the substrate S are placed on the attachments 8.

The operation of this reflow apparatus will be described. As shown in FIG. 5, a substrate S on which chips P are mounted is conveyed to the right by a conveyor 4. Meanwhile, the substrate S sequentially passes through the preheating zone T1, the soaking zone T2, and the reflow zone T3, and the heat of the heater 5 is blown onto the upper surface of the substrate S by the fan 6 in the zones T1, T2, T3.
Is heated and the solder 28 is melted. Next, the substrate S is cooled by the fan 6 of the cooling chamber 10, the solder 28 is solidified, and the chip P is soldered to the electrode of the substrate S.

[0005]

By the way, since the temperature of the substrate S becomes a high temperature of about 230 ° C. due to the heat of the heater 5, the substrate S is thermally deformed during transportation, and as shown by a chain line in FIG. There is a problem in that it is warped downward due to its own weight and is easily hit by the hot air of the fan 6 and easily falls from the conveyor 4. Further, there is a problem in that the substrate S is permanently deformed due to this thermal deformation and is likely to become a defective substrate.

As a means for preventing the substrate S from dropping from the conveyor 4, it is conceivable to lengthen the length L of the attachment 8 to increase the support width of the substrate S. However, the substrate S sent to the reflow apparatus is not only a single-sided mounting substrate having the chip P mounted on one side but also a double-sided mounting substrate having the chip P mounted on the upper and lower surfaces. In the case of a substrate, if the attachment 8 is lengthened, the attachment 8 hits the chip P on the lower surface of the substrate S, so that the length L of the attachment 8 is also limited.

Therefore, an object of the present invention is to provide a reflow apparatus which can prevent the substrate from being deformed and warped or dropped from the conveyor due to the heat of the heater while the substrate is being conveyed in the heating chamber.

[0008]

According to the present invention, a conveyor provided in a heating chamber is provided with a pair of left and right guide rails for guiding both side ends of a substrate, and both side ends of the substrate are pressed against the guide rails from above. The pressing means and the carrying means for carrying the board by sliding the board on the guide rails.

[0009]

According to the above construction, since both side edges of the substrate are pressed by the guide rails by the pressing means to be conveyed in the heating chamber, the substrate is deformed by the heat of the heater during the conveyance and warped, or is conveyed from the conveyor. It can be prevented from falling.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view of the reflow apparatus. Inside the heating chamber 1, there is provided a conveyor 11 that conveys the substrate S on which the chips P are mounted from the inlet 2 to the outlet 3. Above the conveyor 11, a heater 5 and a fan 6 are provided. . 29 is a motor for driving the fan 6. The inside of the heating chamber 1 is divided into a preheating zone T1, a soaking zone T2, and a reflow zone T3 by two partition walls 30, and a cooling chamber 10 is provided at the rear of the heating chamber 1. A front conveyor 12A is provided on the carry-in side of the heating chamber 1, and a rear conveyor 12B is provided on the carry-out side of the heating chamber 1. Next, the structure of the conveyor 11 will be described in detail with reference to FIGS. 1 and 2.

In FIG. 2, the conveyor 11 is mainly composed of a pair of left and right fixed guide rails 13 and a movable guide rail 14 which serve as a conveyance path for the substrate S. Fixed guide rail 1
3 and the movable guide rail 14 are L-shaped in cross section, and a heat insulating material 31 serving as a sliding surface of the substrate S is provided on the lower upper surface thereof. The heat insulating material 31 is made of a heat resistant synthetic resin having a small friction coefficient so that the substrate S can slide smoothly. The heat insulating material 31 is provided on the guide rails 13 and 14 in this manner because the guide rails 13 and 14 are formed of a metal having a small specific heat such as stainless steel or aluminum in order to secure the strength thereof, and therefore the guide rails 13 and 14 are provided at the time of reflow. The rails 13 and 14 absorb the heat of the heater 5 and become extremely hot, and the heat of the guide rails 13 and 14 becomes excessively high.
This is to prevent excessive heat from being locally transmitted to both end portions of the both sides by being transmitted.

On the upper surfaces of the fixed guide rail 13 and the movable guide rail 14, leaf springs 15 as pressing means for pressing both end portions of the substrate S against the guide rails 13 and 14 from above are provided.
Is installed. The leaf springs 15 press the side edges of the board S with the guide rails 13 and
It is pressed against 14, and has a shape in which the lower end portion is curved downward in the carrying-out direction of the substrate S. The leaf springs 15 are fixed to the positions facing the guide rails 13 and 14 with screws 16 at regular intervals.

In FIGS. 1 and 2, a board S is provided below the fixed guide rail 13 and the movable guide rail 14.
A belt conveyor 17 is provided as a conveying means for conveying the paper along the guide rails 13 and 14. The belt conveyor 17 includes a driving timing pulley 18 provided outside the inlet 2 of the heating chamber 1 and an outlet 3 of the heating chamber 1.
A timing belt 20 is attached to a driven timing pulley 19 provided outside the device. The timing belt 20 is a belt made of a heat-resistant material, and the substrate S is formed on the outer peripheral surface of the timing belt 20 at regular intervals.
A feed pin 21 that pushes out is provided. Motor 22
When the timing belt 20 is rotated by driving, the feed pin 21 contacts the rear portion of the substrate S placed on the guide rails 13 and 14, and pushes the substrate S to the right. next,
With reference to FIG. 3, the space adjusting means between the guide rails 13 and 14 will be described.

FIG. 3 is a sectional view of the heating chamber 1. The movable guide rail 14 is attached to the upper end of an inverted L-shaped bracket 32, and a slider 33 is provided below the bracket 32. This slider 33 is the heating chamber 1
Is fitted to the Y-direction rail 34 provided on the lower surface of
A ball screw 36 is bridged through bearings 35 provided on both side surfaces of the heating chamber 1, and a nut 37 mounted on a bracket 32 is screwed onto the ball screw 36.
When the motor 38 is driven to rotate the ball screw 36,
The bracket 32 moves along the Y-direction rail 34 and the movable guide rail 14 slides in the lateral direction, so that the distance between the fixed guide rail 13 and the movable guide rail 14 is adjusted according to the lateral width of the substrate S.

Next, the operation of this reflow apparatus will be described.
In FIG. 1, the substrate S on which the chip P is mounted is carried into the conveyor 11 in the heating chamber 1 from the front conveyor 12A, and the substrate S is conveyed rightward in the heating chamber 1 by the feed pin 21. In the meantime, the substrate S is heated in the preheating zone T1 and the soaking zone T
2, the reflow zone T3 is sequentially passed, and hot air is blown by the fan 6 in the zones T1, T2, T3 by the fan 6.
Is sprayed onto the upper surface of the substrate S to heat the substrate S, and the solder 28 is melted.

The substrate S tends to warp downward due to its own weight due to the heat at this time, but since both end portions of the substrate S are pressed against the upper surface of the heat insulating material 31 by the leaf springs 15 from above, the deformation thereof occurs. Be blocked. That is, as the substrate S is thermally deformed, both end portions of the substrate S try to float above the upper surface of the heat insulating material 31, but the floating force is restricted by the pressing force of the leaf spring 15 and the deformation of the substrate S is prevented. Therefore, it is possible to prevent the warp of the substrate S during the transportation. Further, by pressing both end portions of the substrate S against the heat insulating material 31 by the leaf springs 15, it is possible to eliminate the substrate S from being hit by the hot air of the fan 6 and falling from the conveyor 4. Next, the substrate S is cooled by the fan 6 of the cooling chamber 10, the solder 28 is solidified, and the chip P is soldered to the electrode of the substrate S.

Further, when the horizontal width of the substrate S changes with the change of the type of the substrate S, the ball screw 36 is rotated by driving the motor 38 in FIG. 3, and the movable guide rail 14 is laterally moved and fixed. The distance between the guide rail 13 and the movable guide rail 14 is adjusted.

The present invention is not limited to the above embodiment, and for example, as shown in FIG.
4 at the upper end of the plate 4 with a leaf spring 42 extending laterally by a screw 41.
The attachment 43 is attached to the tip of the leaf spring 42, and the pressing roller 44 is axially attached to the attachment 43 so that the pressing force of the leaf spring 42 pushes the pressing roller 44 to both end portions of the substrate S. You may do it. Further, in FIG. 3, when the movable guide rail 14 is slid to adjust the distance between the guide rails 13 and 14,
The timing belt 20 may be slid by a half of the stroke of the movable guide rail 14 in conjunction with the sliding movement of the movable guide rail 14. With this arrangement, the feed pin 21 always moves the substrate S. You can send the center. As the sliding means of the timing belt 20, the sliding means similar to that of the movable guide rail 14 can be applied. Further, although the above embodiment has been described by taking the air reflow device as an example, in order to prevent the oxidation of the metal part such as the circuit pattern of the substrate, the inert gas atmosphere is supplied while supplying the inert gas such as nitrogen gas. It can also be applied to a nitrogen reflow device that heats solder.

[0019]

According to the present invention, a conveyer for conveying a substrate in a heating chamber is provided with a pair of left and right guide rails for guiding both side ends of the substrate and pressing means for pushing both side ends of the substrate against the guide rails from above. Since the substrate is configured to be transported by sliding the substrate on the guide rail, the substrate is thermally deformed by the heat of the heater while the substrate is transported in the heating chamber to become a defective substrate. It is possible to prevent the substrate from warping and dropping from the conveyor.

[Brief description of drawings]

FIG. 1 is a sectional view of a reflow apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part in a heating chamber of a reflow device according to an embodiment of the present invention.

FIG. 3 is a sectional view of a heating chamber of the reflow apparatus according to the embodiment of the present invention.

FIG. 4 is a sectional view of an essential part of a heating chamber of a reflow device according to another embodiment of the present invention.

FIG. 5 is a sectional view of a reflow device according to a conventional means.

FIG. 6 is a sectional view of a conveyor of a reflow device according to a conventional means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating chamber 5 Heater 6 Fan 11 Conveyor 13,14 Guide rails 15,42 Pressing means (leaf spring) 17 Conveying means 43 Pressing means (attachment) 44 Pressing means (pressing roller) S Substrate

Claims (2)

[Claims] 1. A reflow apparatus comprising a heating chamber, a heater and a fan provided in the heating chamber, and a conveyer provided in the heating chamber to convey a substrate from an inlet to an outlet of the heating chamber. The conveyor, a pair of left and right guide rails for guiding both end portions of the board, and pressing means for pressing both end portions of the board against the guide rails from above,
A reflow apparatus comprising: a transfer unit configured to transfer a substrate by sliding on the guide rail. 2. The reflow apparatus according to claim 1, wherein the pressing means is a spring material and is attached to the guide rail.