JPH05262U - Inert gas reflow equipment - Google Patents

Abstract

(57) [Summary] [Structure] A plurality of preheating chambers 13, reflow chambers 14 and cooling chambers 21 are formed inside the furnace 11 by partition plates 12.
A fan 15 and a heater 16 are provided in the preheat chamber 13 and the reflow chamber 14, and a fan 22 and a heat exchanger 23 are provided in the cooling chamber 21. Cooling water is supplied to the tubes of the heat exchanger 23.
When nitrogen gas is injected into the furnace through an injection port 17 provided in the furnace 11, the nitrogen gas expands throughout the furnace to form an inert atmosphere. While the surface mount substrate P is being conveyed by the conveyor 20, the substrate P is preheated by the heater 16 in the preheat chamber 13, the solder paste of the substrate P is reflowed in the reflow chamber 14 at 220 to 230 ° C., and the cooling chamber at 80 to 120 ° C.
Quench the board at 21. [Effect] Since the nitrogen atmosphere convected by the fan 22 in the cooling chamber 21 is controlled to a low temperature by the heat exchanger 23,
The reflow soldered substrate P can be rapidly cooled in a nitrogen atmosphere.

Description

[Detailed description of the device]

[Purpose of Invention]

[0002]

[Industrial applications]

 The present invention relates to an inert gas reflow device that uses an inert gas such as nitrogen gas.

[0003]

[Prior Art]

 As shown in FIG. 2, a plurality of preheating chambers 13 and reflow chambers 14 are formed inside the furnace 11 by a partition plate 12, and fans 15 and heaters 16 are provided in the chambers 13 and 14, respectively. There is an inert gas reflow device in which an inlet 17 for an inert gas such as nitrogen is provided in the upper part of. The inert gas such as nitrogen injected from the injection port 17 into one preheat chamber 13 is expanded to the other preheat chamber 13 and the reflow chamber 14. Then, while the surface-mounting substrate P as a work is transported by the substrate transporting conveyor 20 penetrating the inside of the furnace from the substrate loading port 18 to the substrate unloading port 19, the heaters 16 heated in the chambers 13 and 14 are not heated. The active gas is blown onto the substrate P by the fan 15, the substrate P is preheated in the preheat chamber 13, and the solder paste of the substrate P is reflowed in the reflow chamber 14 by a higher temperature inert gas. The reflow performed in an inert atmosphere of nitrogen or the like has an advantage that solder oxidation is prevented.

[0004]

[Problems to be solved by the device]

 However, in order to improve the soldering quality by rapid cooling after melting the solder, conventionally, the substrate after reflow is carried out as it is to the outside of the furnace and forcedly cooled by an outside air fan. Even if reflow is performed in an active atmosphere, there is a problem of oxidation immediately after reflow. On the other hand, when the work is cooled in the furnace, there is a problem that the reflow chamber is easily affected by heat conduction and high temperature atmosphere.

The present invention has been made in view of the above circumstances, and an object thereof is to enable rapid cooling in an inert atmosphere.

[Constitution of Device]

[0007]

[Means for Solving the Problems]

 The present invention is an inert gas reflow apparatus in which a plurality of preheat chambers 13 and reflow chambers 14 are partitioned by partition plates 12 in a furnace 11 into which an inert gas is injected, along a conveyor 20 for transferring a work. In the furnace, the cooling chamber 21 partitioned by the partition plate 12 on the downstream side of the reflow chamber 14 and the ambient temperature difference between the cooling chamber 21 provided in the cooling chamber and the upstream reflow chamber 14 are 100 ° C. It is an inert gas reflow device equipped with a heat exchanger 23 that keeps the temperature above a certain level.

[0008]

[Action]

 According to the present invention, the heat exchanger 23 controls the temperature of the inert atmosphere in the cooling chamber 21 to a temperature lower than the temperature difference of about 100 ° C. with the reflow chamber 14, and the reflow soldering is performed in the reflow chamber 14. The work P is forcibly cooled in the cooling chamber 21.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiment shown in FIG.

A plurality of preheating chambers 13, a reflow chamber 14, and a cooling chamber 21 are sequentially formed in the furnace 11 by a partition plate 12. A fan 15 and a heater 16 are provided in each preheat chamber 13 and reflow chamber 14. Further, a fan 22 and a heat exchanger 23 located below the fan 22 are provided in the cooling chamber 21 defined inside the furnace and downstream of the reflow chamber 14. Cooling water, low-temperature air, gas, etc. are supplied to the tubes of the heat exchanger 23.

An inlet 17 for an inert gas such as nitrogen is provided in the center of the furnace 11. The inert gas such as nitrogen injected from the injection port 17 into one preheat chamber 13 is expanded to the other preheat chamber 13, reflow chamber 14 and cooling chamber 21. Further, a substrate loading port 18 and a substrate loading port 19 are provided on one side and the other side of the furnace 11, and a conveyor 20 for transporting a work that penetrates through the furnace from the substrate loading port 18 to the substrate loading port 19 is provided. Has been.

Then, while the conveyor 20 conveys the surface-mounted substrate P as a work, in the preheat chamber 13 and the reflow chamber 14, an inert gas such as nitrogen heated by the heater 16 is fed by the fan 15 to the substrate. The substrate P is preheated by the heat of the inert gas of about 150 ° C. in the plurality of preheating chambers 13 and is heated by the high temperature inert gas of about 220 to 230 ° C. in the reflow chamber 14. The solder paste on the substrate P is reflowed.

Further, since the temperature of the inert atmosphere convected by the fan 22 in the cooling chamber 21 is controlled to a low temperature of about 80 to 120 ° C. by the heat exchanger 23, it is about 220 to 230 ° C. in the reflow chamber 14. When the reflow-soldered substrate P is carried into the cooling chamber 21 in the high temperature atmosphere, it is rapidly cooled by a low temperature inert atmosphere having an ambient temperature difference of 100 to 150 ° C. from the reflow chamber 14. . The temperature difference of about 100 ° C. is a temperature difference necessary for quenching the substrate P without being affected by the high temperature reflow chamber 14, and the temperature difference of about 150 ° C. is a heat shock of the board mounted component. , The temperature difference determined in consideration of the thermal influence on the reflow chamber 14.

[0014]

[Effect of the device]

 According to the present invention, the work can be forcibly cooled in the inert atmosphere in the cooling chamber controlled by the heat exchanger at a temperature lower than the ambient temperature difference between the reflow chamber and about 100 ° C. Work can be rapidly cooled in an inert atmosphere without being significantly affected.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the inert gas reflow apparatus of the present invention.

FIG. 2 is a cross-sectional view of a conventional inert gas reflow device.

[Explanation of symbols]

 11 Furnace 12 Partition plate 13 Preheat chamber 14 Reflow chamber 20 Conveyor 21 Cooling chamber 23 Heat exchanger

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location B23K 101: 42 (72) Creator Yasuo Miyamoto 11 Tamura Co., Ltd., 591, Kamihirose Higashikubo, Sayama City, Saitama Prefecture Inside the Machinery Works of Mfg. Co., Ltd. (72) Inventor Toshiya Uchida 11 at 591 Kamihirose Higashikubo, Sayama City, Saitama Inside Tamura Co., Ltd. Machinery Works

Claims (1)

[Claims for utility model registration] [Claim 1] An inert gas in which a plurality of preheat chambers and reflow chambers are partitioned by partition plates along a conveyor for transferring a work in a furnace into which an inert gas is injected. In the gas reflow apparatus, a cooling chamber defined by a partition plate on the downstream side of the reflow chamber in the furnace and an ambient temperature difference between the cooling chamber provided in the cooling chamber and the upstream reflow chamber are about 100 ° C. An inert gas reflow apparatus, comprising: a heat exchanger maintained as above.