JPH0768372A - Inert atmosphere soldering device - Google Patents

Abstract

PURPOSE:To provide the inert atmosphere soldering device capable of satisfying the high reliability required in soldering of products associated with computers, etc., by removing the fine solder particles suspended in an inert atmosphere. CONSTITUTION:A circulation route of the inert atmosphere is formed by a centrifugal fan 12 and right and left guides 13 within a furnace body 11 into which gaseous nitrogen for preventing oxidation is introduced. A heater 14 and a conveyor 15 for a work W are disposed between the right and left guides 13. Inside wall plates 31 of the furnace body are freely attachably and detachably mounted at the right and left inside wall parts of the furnace body 11 by bolts 32. A part or the whole of the furnace body 11, guides 13 and inside wall plates 31 of the furnace body constituting the reflow furnace are composed of materials, such as gold, tin, silver, palladium, copper, bronze or brass, having wettability with solder. The solder particles in the furnace are adsorbed away by the metallic surfaces of the inside walls of the furnace body 11, the guides and the inside wall plates 31 of the furnace body heated by the hot air circulating in the furnace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering apparatus for soldering in a space where an inert atmosphere is maintained.

[0002]

2. Description of the Related Art A reflow type soldering apparatus shown in FIG. 3 forms an atmosphere circulation path inside a furnace body 11 by a centrifugal blower 12 and a guide 13, and a heater 14 is provided in this circulation path.
Further, a conveyor 15 is provided, and infrared rays radiated from the heater 14 and a high-temperature atmosphere heated by the heater 14 are applied to the work W conveyed by the conveyor 15 to reflow the solder paste of the work W. This furnace body 11
In order to prevent the oxidation of the solder, nitrogen gas or the like is injected into the inside of the to maintain an inert atmosphere.

The flow type soldering apparatus shown in FIG. 4 has a fluxer 2 along a conveyor 21 that conveys a work W.
2. A preheater 23 and a jet type solder bath 24 are arranged, and these are covered by a chamber body 25, and the chamber body
Nitrogen gas or the like is injected into 25 to maintain an inert atmosphere to prevent solder oxidation.

The inert atmosphere space forming members such as the furnace body 11 and the chamber body 25 are made of iron plate or stainless steel plate.

[0005]

In these inert atmosphere soldering devices, fine solder particles are suspended in the furnace body 11 or the chamber body 25, but the surface of the solder particles is suspended due to the inert atmosphere. In the region where the oxide film is not formed and the ambient temperature exceeds the melting point of the soldering material, the solder particles melt and adhere to the product work W, which is a defect.

For example, the connector portion of the computer board is provided with a gold-plated portion, but if the solder particles adhere to that portion, there is a problem that the connector connection reliability decreases.

The present invention has been made in view of the above circumstances, and is required for soldering computer-related products by removing fine solder particles floating or about to float in an inert atmosphere. It is an object of the present invention to provide an inert atmosphere soldering device capable of satisfying the high reliability required.

[0008]

The invention described in claim 1 is a reflow furnace constituting a reflow furnace in an inert atmosphere soldering apparatus for soldering in a reflow furnace in which an inert atmosphere is maintained. Some or all of the constituent members are made of a material having solder wettability.

According to a second aspect of the present invention, the reflow furnace constituent member having the solder wettability according to the first aspect is detachably provided.

According to a third aspect of the present invention, in an inert atmosphere soldering apparatus in which a solder is jetted from a solder bath in a chamber in which an inert atmosphere is maintained, a chamber structure constituting the chamber is provided. Part or all of the member is made of a material having solder wettability.

According to a fourth aspect of the present invention, a heater is integrally provided on the chamber constituent member having the solder wettability according to the third aspect.

[0012]

According to the invention described in claim 1, the reflow oven constituent member heated to a temperature equal to or higher than the melting point of the solder by the atmosphere in the furnace allows the solder particles floating in the reflow oven to be wetted by the solder of the reflow oven constituent member itself. Adsorbs due to its nature and filters the inside of the furnace.

According to the second aspect of the present invention, when the adsorption capability of the reflow furnace component having solder wettability reaches a saturated state, it is replaced with a new one.

According to the third aspect of the present invention, the chamber constituent member heated to a temperature equal to or higher than the melting point of the solder due to heat conduction from the solder bath or the like is the solder particles which are about to diffuse or diffuse into the chamber from the solder bath. Solder particles,
It is adsorbed and removed by the solder wettability of the chamber constituent member itself.

According to the invention described in claim 4, even when the temperature of the inert atmosphere is lower than the melting point of the solder, the solder particles are adsorbed and removed by the wettability of the chamber constituent members heated by the heater. .

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in FIGS.

FIG. 1 shows an example in which the present invention is applied to a reflow type soldering apparatus. Inside a furnace body 11 in which an inert atmosphere is maintained by injecting nitrogen gas or the like in order to prevent oxidation of the soldering material. A centrifugal air blower 12 and left and right guides 13 form a circulation path of an inert atmosphere, and a heater 14 and a work transfer conveyor 15 are provided between the left and right guides 13 that are part of this circulation path.

Then, infrared rays radiated from the heater 14 and a high-temperature atmosphere heated by the heater 14 are applied to the work W conveyed by the conveyor 15 to reflow the solder paste of the work W and perform soldering.

In the reflow furnace in which the inert atmosphere is maintained, a part or all of the furnace body 11 and the guides 13 as the reflow furnace constituent members constituting the reflow furnace are made of a material having solder wettability.

Further, the left and right inner wall portions of the furnace body 11 also have inner walls of the furnace body as a reflow furnace constituent member having solder wettability.
31 is detachably attached with bolt 32.

Hereinafter, the furnace body 11, the guide 13 and the wall plate inside the furnace body
31 is called a reflow furnace constituent member 11, 13, 31.

If the soldering material of the solder paste is eutectic solder, the reflow furnace components 11, 13 and 31 having good solder wettability are gold, tin and silver which are easily wettable by the soldering material. Use palladium, copper, bronze or brass.

For example, gold, tin, silver or palladium may be plated on the reflow furnace components 11, 13, 31 and copper, bronze or brass may be plated on the reflow furnace components 11, 13, 31. It is good to use a plate.

Further, the detachable reflow oven constituent member 31 may be a smooth metal-plated plate or a smooth-surfaced metal plate as described above, but a three-dimensional net structure is formed by using the metal material as described above. A molded porous metal plate may be used.

In the structure shown in FIG.
Since the reflow furnace constituent members 11, 13, 31 have reached a temperature equal to or higher than the melting point of the soldering material due to the high temperature inert atmosphere in the reflow furnace, the solder particles floating in the inert atmosphere in the furnace are When it comes into contact with the high temperature surface of the reflow furnace constituent member 11, 13, 31, it is adsorbed to the smooth metal surface or porous metal surface having solder wettability and filtered.

In the reflow furnace constituent members 11, 13 and 31, the metal surface in contact with the inert atmosphere is not easily oxidized, and the oxide film on the metal surface is removed by the cleaning action of the flux contained in the atmosphere. The solder wettability can be ensured continuously.

When the detachable reflow oven constituent member 31 is formed of a porous metal plate having a three-dimensional network structure, the molten solder can be absorbed into the three-dimensional network porous body for a certain period, but its absorption capacity is saturated. It is good to replace it with a new one when it reaches.

Incidentally, as shown in FIG. 1, the centrifugal blower 12
The structure in which the detachable reflow furnace constituent member 31 is arranged at the position where the wind discharged from the device hits is an effective mode for maintenance, but the present invention is not limited to such a structure.

Next, FIG. 2 is an example in which the present invention is applied to a flow type soldering apparatus, and a conveyor for conveying a work W.
A fluxer 22, a preheater 23, and a jet-type solder bath 24 are arranged along the line 21, and these are covered by a chamber body 25, and nitrogen gas or the like is injected into the chamber body 25 to maintain an inert atmosphere. The molten solder jetted from 24 is prevented from being oxidized.

A skirt portion 41 is integrally provided on the chamber body 25, and the skirt portion 41 is used in the jet solder bath 24.
This skirt part 41 is inserted in the molten solder of
Metal plate with solder wettability so that it adheres to the upper part of the
Install 42.

The chamber main body 25, the skirt portion 41 and the metal plate 42 are chamber constituent members constituting the chamber, and at least the metal plate 42 is a material having solder wettability, that is, the reflow furnace constituent members 11, 13, It is composed of the same material as 31.

The surface temperature of the metal plate 42 can be higher than the melting point of the soldering material due to heat conduction through the skirt portion 41 inserted into the molten solder of the solder bath 24, so that the solder wettability is temporarily secured. it can.

Further, a heater 44 is integrally provided on the metal plate 42 via a heat transfer block 43 so that the surface temperature of the surface of the metal plate 42 equal to or higher than the melting point of the soldering material can be obtained. .

The solder particles, which are about to diffuse into the chamber body 25 from the jet solder surface or its falling wave surface, are higher than the melting point of the soldering material due to heat conduction from the molten solder in the solder bath 24 and heating by the heater 44. When it comes into contact with the metal plate 42 whose temperature has risen, it is adsorbed on the surface of the metal plate 42 having solder wettability, grows on this surface and falls into the solder bath 24 by its own weight.

In the embodiment of FIG. 2, the metal plate 42, which is separate from the chamber body 25, is made of a material having solder wettability as a chamber constituent member. The whole or only the skirt portion 41 may be made of a material having the same solder wettability.

For example, when the entire chamber body 25 is made of a metal material having solder wettability, the chamber body 25
If the entire 25 is heated by the heater, the solder particles diffused in the chamber body 25 can be adsorbed and removed by the chamber body 25 itself.

When only the skirt portion 41 is partially made of a material having solder wettability, a separate metal plate 42 is used.
Is unnecessary, and a projecting piece such as the metal plate 42 may be integrally formed on the skirt portion 41.

[0038]

According to the invention described in claim 1, since a part or all of the reflow furnace constituent member is made of a material having solder wettability, the reflow furnace constituent member having a temperature higher than the melting point of the solder is obtained. It itself functions as a filter for adsorbing and removing the solder particles in the furnace, adsorbing and removing the solder particles floating in the inert atmosphere space, and preventing the reliability from being lowered due to the adhesion of the solder particles to the product. Further, as compared with the case where the in-furnace solder particle adsorption filter is arranged so as to block the hot air circulation passage, there is no obstacle to the hot air circulation, so the pressure loss of the hot air is small.

According to the second aspect of the present invention, since the reflow furnace constituent member having solder wettability is detachably provided, when the adsorption capacity of the reflow furnace constituent member reaches the saturated state, it is replaced with a new one. Can be replaced with a longer life.

According to the third aspect of the present invention, since a part or all of the chamber constituent members for keeping the periphery of the solder jetted from the solder bath in an inert atmosphere are made of a material having solder wettability, The solder particles which are about to diffuse into the chamber from the solder bath or the diffused solder particles can be adsorbed and removed by the solder wettability of the chamber constituent member itself.

According to the invention described in claim 4, even when the surface temperature of the chamber constituent member for adsorbing the solder particles is equal to or lower than the melting point of the solder, the chamber constituent member is heated by the heater to obtain the solder wettability. It is possible to maintain the temperature, and there is an advantage that it can be used even in a place where the temperature of the inert atmosphere is lower than the melting point of the solder.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing an embodiment of a flow type soldering device according to the present invention.

FIG. 3 is a sectional view showing a conventional reflow soldering device.

FIG. 4 is a cross-sectional view showing a conventional flow soldering device.

[Explanation of symbols]

 11, 13, 31 Reflow furnace components 25, 41, 42 Chamber components 44 Heater

Claims (4)

[Claims] 1. An inert atmosphere soldering device for soldering in a reflow furnace in which an inert atmosphere is maintained, wherein a part or all of the reflow furnace constituent members constituting the reflow furnace have solder wettability. An inert atmosphere soldering device characterized by being composed of materials. 2. The inert atmosphere soldering device according to claim 1, wherein a reflow oven constituent member having solder wettability is detachably provided. 3. An inert atmosphere soldering apparatus, in which a solder jetted from a solder bath performs soldering in a chamber in which an inert atmosphere is maintained, wherein some or all of chamber constituent members constituting the chamber are An inert atmosphere soldering device comprising a material having solder wettability. 4. The inert atmosphere soldering device according to claim 3, wherein a heater is integrally provided on the chamber constituent member having solder wettability.