JPH0577036A - Nitrogen reflow apparatus - Google Patents

Abstract

PURPOSE:To prevent flow of the outer air into a heating furnace from an inlet part and an outlet part. CONSTITUTION:In a nitrogen reflow apparatus providing a heating chamber 1 setting heaters 2 and fans 3, a conveyor 4 for carrying a substrate S from the inlet part 5 to the outlet part 6, a nitrogen gas supplying part 7 for supplying the nitrogen gas N2 in the above heating chamber 1, blasting direction adjusting means 13, 14, 15 for adjusting the blasting direction of the above nitrogen gas N2 are arranged in the above heating chamber 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chisso reflow device, and more particularly to a means for preventing external air from flowing into an inside of a heating chamber from an inlet portion or an outlet portion thereof and increasing an oxygen concentration in the heating chamber. ..

[0002]

2. Description of the Related Art When mounting electronic components on a substrate, cream solder is applied to the electrode portion of a circuit pattern such as a copper foil formed on the substrate, the electronic components are bonded onto the cream solder, and then this substrate is mounted. Is sent to the reflow device and the heat treatment of the cream solder is performed.

Conventionally, such heat treatment of solder has been performed by heating air. However, since oxygen is contained in the air, the circuit pattern made of copper foil or the like and the cream solder are heated. Therefore, there is a problem that the wetting property of the solder is deteriorated by the oxidation, and the electronic component cannot be properly adhered to the substrate.

As a remedy for this problem, there has been proposed a chisso reflow apparatus for performing heat treatment in a nitrogen gas atmosphere in which there is no fear of oxidation of the circuit pattern or cream solder.

A conventional chisso reflow apparatus will be described with reference to FIG. The substrate 104 is conveyed by the conveyer 103 into the heating chamber 102 in which the heater 100 and the fan 101 are arranged, and the heater 100 heats the cream solder. The inside of the heating chamber 102 is partitioned by partition walls 111 and 112 into a preheating zone 108, a soaking zone 109 having a relatively high uniform temperature, and a high-temperature melting zone 110 for melting the cream solder. Each zone 1 from the Chisso gas supply means 105
It is always supplied within 08-110. Reference numeral 106 is an inlet portion of the heating chamber 102, and 107 is an outlet portion.

[0006]

However, the nitrogen gas N2 supplied into the heating chamber 102 is supplied to each fan 10
After being blown downwards by 1, usually the inlet section 106
In addition, the air flows out from the outlet 107 to the outside evenly in small amounts.
From the inlet 106 to the outlet 107 as in 1,
There is a possibility that a unidirectional flow of the nitrogen gas N2 from the outlet portion 107 toward the inlet portion 106 may occur as shown by the arrow N2. When the unidirectional flow of the nitrogen gas N2 due to such a tunnel effect occurs, not only the nitrogen gas N2 in the heating chamber 102 flows out in large quantities from the outlet 107 and the inlet 106, but also as shown by the broken line arrow in FIG. The outside air E flows into the heating chamber 102 from the inlet 106 or the outlet 107 by riding on the one-way flow of the nitrogen gas N2,
For this reason, there is a problem that the oxygen concentration in the heating chamber 102 gradually increases, which causes a problem due to the above-described oxidation of the circuit pattern and cream solder.

Therefore, an object of the present invention is to provide a chisso reflow device which can prevent external air from flowing into the heating chamber to increase the oxygen concentration in the heating chamber.

[0008]

According to the present invention, there is provided a heating chamber in which a heater and a fan are arranged, a conveyer for carrying a substrate from an inlet portion to an outlet portion of the heating chamber, and a nitrogen gas supply to the heating chamber. In a chisso reflow device provided with a nitrogen gas supply part, an air flow direction adjusting means for adjusting the air flow direction of the nitrogen gas is provided in the heating chamber.

[0009]

In the above structure, the wind direction adjusting means adjusts the wind direction of the nitrogen gas flowing through the heating chamber so that the nitrogen gas supplied into the heating chamber flows out from both the inlet portion and the outlet portion. Directional flow is prevented from occurring, and therefore, the external air due to the tunnel effect is prevented from flowing into the heating chamber from the inlet portion or the outlet portion and increasing the oxygen concentration in the heating chamber.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a side view of a chisso reflow device. Reference numeral 1 is a heating chamber, and a heater 2 is provided above the inside of the heating chamber.
A fan 3 is arranged. Reference numeral 4 denotes a conveyor arranged in the heating chamber 1, and conveys the substrate S on which the electronic component P is mounted from the inlet portion 5 toward the outlet portion 6. Reference numeral 7 is a nitrogen gas supply means for supplying nitrogen gas N2 into the heating chamber 1, and constantly supplies nitrogen gas N2 to the preheating zone 8, the soaking zone 9 and the melting zone 10 provided in the heating chamber 1. Reference numerals 11 and 12 are partition walls that divide the zones 8 to 10, and reference numerals 13 and 14 are dampers as wind direction adjusting means for the Chisso gas N2.
Side and the melting zone 10 side. Reference numeral 15 is a shower portion for cooling the heated substrate S, which is connected to the nitrogen gas supply means 7 and is pivotally mounted in the heating chamber 1 by a pin 16 so that the angle can be adjusted. Reference numeral 17 is a cylinder for rotating the shower unit 15. When the cylinder 17 is driven to project and retract the rod 18, the tip of the rod 18 presses the shower unit 15 and rotates the shower unit 15, thereby adjusting the angle of the shower unit 15. These component parts 15 to 18 constitute a wind direction adjusting means different from the dampers 13 and 14.

The present apparatus has the above-mentioned structure, and its operation will be described below. In FIG. 1, the substrate S transferred to the conveyer 4 enters the heating chamber 1 through the inlet portion 5, and then the solder is heated by the heater 2 while sequentially passing through the preheating zone 8, the soaking zone 9, and the melting zone 10. After that, the substrate S is cooled by blowing nitrogen gas from the shower portion 15 and is carried out of the heating chamber 1 through the outlet portion 6.

During this series of operations, each zone 8, 9, 10
Chisso gas N2 is supplied from the nitrogen gas supply means 7, and the supplied nitrogen gas N2 is blown onto the substrate S flowing on the conveyor 4 by the fan 3. By the way, when the flow of the nitrogen gas N2 is viewed from the entire heating chamber 1, as described in the section of the problem to be solved by the invention, from the inlet portion 5 to the outlet portion 6 or from the outlet portion 6 to the inlet portion 6. A unidirectional flow of nitrogen gas N2 tends to be generated toward 5. Therefore, this flow is blocked by changing the rotation angles of the dampers 13 and 14 and the shower unit 15. Specifically, when the flow from the inlet portion 5 to the outlet portion 6 is generated as shown by the arrow N1, the rotation angle of the damper 13 on the inlet portion 5 side is increased as shown by the solid line in the figure to preheat The wind direction of the nitrogen gas N2 in the zone 8 is directed to the inlet portion 5 side, the rotation angle of the damper 14 on the outlet portion 6 side is reduced, and the rod 17 is projected by driving the cylinder 17 so that the nitrogen gas from the shower portion 15 is discharged. The flow direction of N2 is directed in the direction of the broken line arrow to suppress the flow of the nitrogen gas N2 toward the outlet portion 6 side in the melting zone 10. Further, in the case of going from the outlet portion 6 to the inlet portion 5 as shown by an arrow N1 ', the rotation angle of the damper 13 is made smaller as shown by the chain line in the figure, and the wind direction of the nitrogen gas N2 in the preheating zone 8 is changed to the outlet portion Toward the side and increasing the rotation angle of the damper 14, the cylinder 17 is driven to pull back the rod 18, and the shower unit 15
By directing the blowing direction of the nitrogen gas N2 from the direction of the solid line arrow, the flow of the nitrogen gas N2 to the inlet portion 5 side in the preheating zone 10 is suppressed.

By performing such adjustment, the flow of the nitrogen gas N2 supplied into the heating chamber 1 is unidirectional from the inlet portion 5 to the outlet portion 6 or from the outlet portion 6 to the inlet portion 5 as in the conventional means. However, the excess nitrogen gas N2 in the windless state flows toward both directions of the inlet portion 5 and the outlet portion 6 such that the small amount of surplus nitrogen gas N2 spontaneously flows out of the heating chamber 1 in a small amount, which is a problem in the conventional means. In addition, the inflow of the external air E into the heating chamber 1 by the unidirectional flow of the nitrogen gas N2 due to the tunnel effect can be prevented by the nitrogen gas N2 flowing out from the inlet portion 5 and the outlet portion 6.

The present invention is not limited to the above-described embodiment. For example, the wind direction may be adjusted only by the dampers 13 and 14 and the wind direction may not be adjusted by the shower unit 15, or the wind direction adjusting means may be dampers 13, 14. 1
The wind direction of the nitrogen gas N2 may be changed by changing the size of No. 4.

[0016]

As described above, according to the present invention, the wind direction adjusting means for adjusting the wind direction of the nitrogen gas is provided in the heating chamber, so that the one-way flow of the nitrogen gas due to the tunnel effect does not flow in the heating chamber. The wind direction of the nitrogen gas can be adjusted to prevent external air from flowing into the heating chamber through these inlets and outlets.

[Brief description of drawings]

FIG. 1 is a side view of a chisso reflow device according to the present invention.

FIG. 2 is a side view of a conventional chisso reflow device.

[Explanation of symbols]

 1 Heating Chamber 2 Heater 4 Conveyor 5 Inlet 6 Outlet 7 Chisso Gas Supply 13 13 Wind Direction Adjusting Means 14 Wind Direction Adjusting Means 15 Wind Direction Adjusting Means N2 Chisso Gas S Substrate

Claims (1)

[Claims] 1. A chisso having a heating chamber in which a heater and a fan are arranged, a conveyor for transporting a substrate from an inlet portion to an outlet portion of the heating chamber, and a nitrogen gas supply portion for supplying nitrogen gas to the heating chamber. In the reflow device, a wind direction adjusting means for adjusting the wind direction of the nitrogen gas is provided in the heating chamber.