JPH06328238A - Jet type soldering apparatus - Google Patents

Abstract

PURPOSE:To improve the efficiency of soldering by executing the continuous soldering in the condition of preventing the oxidation of solder without using flux, in the soldering of electronic parts, etc., in a jet type soldering apparatus. CONSTITUTION:At both right and left sides inserting a conveying rail 9, blowing holes 11 for blowing inert gas of nitrogen gas, etc., toward a spouting hole 3 for molten solder C are arranged. While blowing inert gas from the blowing hole 11, the electronic parts A are continuously passed in the solder jet stream. As the surroundings of the solder jet stream is kept to inert gas atmosphere by the inert gas blown from the blowing holes 11 at both right and left sides, the soldering can continuously be executed in the condition of preventing the oxidation of the solder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a jet type soldering device used for soldering electronic parts and the like.

[0002]

2. Description of the Related Art In an electronic component such as a network resistor in which an element such as a resistor is mounted on one or both sides of a substrate made of ceramic or the like, an element or a lead wire is soldered to a circuit on the substrate. As a means for solder plating on a printed circuit board or a printed circuit board, the molten solder is ejected upward from the ejection port provided in the solder bath, and the electronic component that has been transferred by the transport rail in the solder jet flow ejected from the ejection port There is used a jet type soldering device which is designed to pass through.

In this case, as shown in FIGS. 13 and 14, the electronic component A is fixed to the tip of a lead portion B1 provided on the hoop-shaped lead frame B at appropriate intervals, and the lead frame B is attached to the lead portion B. The lead frame B is attached to the carrier rail 20 so as to extend downward, and the lead frame B is allowed to pass through the molten solder C ejected from the ejection port 21 while the lead frame B is conveyed along its longitudinal direction.

As means for removing the effect of solder oxidation, conventionally, there are means for soldering in an inert atmosphere as shown in FIG. 13 and means for using flux as shown in FIG. Was adopted. That is, FIG. 13 shows that the part where the solder bath 22 is installed and the parts on the front and rear sides of the solder bath 22 along the transfer direction of the electronic component C are partitioned by shutters 23 that can be opened and closed. The first, second, and third sealed chambers 24, 25, and 26 are configured in this order from the front along the transfer direction of A, and each sealed chamber 24, 25, and 26 is filled with nitrogen gas, or The closed chamber 25 is filled with nitrogen gas so that the first and second
By maintaining the sealed chambers 24 and 26 in a vacuum state, the second sealed chamber 25 for soldering is maintained in an inert atmosphere, while the lead frames B are transferred by the transfer in the second sealed chamber 25. The electronic components A are divided into short lengths so that they can pass through the solder jet, and the lead frames B divided into these short lengths are opened / closed by the shutter 22, so that the first and second , Third closed chamber 24, 2
It is designed to be intermittently transferred into the inside of 5, 26.

Further, FIG. 14 shows that the lead frame B is configured to be continuously transferred without being divided.
A flux coating device 27 is provided in a portion in front of the solder bath 21 in the transfer direction of the electronic component C, and excess flux is provided in a portion in front of the solder bath 22 in the transfer direction of the electronic component A. A cleaning device 28 for removing is provided.

[0006]

However, since the means of FIG. 13 does not require the flux and its cleaning process,
It has the advantage of not causing the harmful effects of flux residues and the problem of environmental damage due to the diffusion of cleaning liquid, but on the other hand, it is a so-called batch process of intermittently soldering a plurality of electronic components A, so the efficiency is extremely low. There was a problem to say.

On the other hand, the means shown in FIG.
Since it can be transferred continuously, the efficiency of soldering is high,
There is a problem that the flux remains in the electronic component A and interferes with the subsequent steps, and that the cleaning solution such as CFCs may be released to the atmosphere in the flux cleaning step, which may cause environmental damage. The present invention has been made in view of such a problem, and an object thereof is to enable efficient soldering without using a flux.

[0008]

In order to achieve this object, the present invention transfers a solder bath having an ejection port for ejecting molten solder upward and a transfer means for continuously transferring an object to be processed. A jet-type soldering device provided so that an object to be processed in the middle passes through a solder jet ejected from the ejection port, in which both sides of the transfer port of the object to be treated are sandwiched in the vicinity of the ejection port. At this portion, there is provided a blowout port configured to blow out an inert gas such as nitrogen gas toward the solder jet flow jetted from the jet port.

[0009]

With this structure, since both outlets are close to the ejection port, the solder jet flow ejected from the ejection port only by ejecting an inert gas such as nitrogen gas from both ejection ports. Since it is possible to maintain an inert atmosphere in the periphery of the, the continuous transfer of the object to be processed while continuously ejecting the inert gas from the outlet makes it possible to oxidize the solder without using flux. It is possible to continuously solder in the prevented state.

Therefore, according to the present invention, there is an effect that soldering of electronic parts and the like can be efficiently performed without causing a bad influence due to the residue of the flux and a problem of environmental destruction due to the cleaning solution of the flux. By the way, when soldering an electronic component by a jet soldering device, excess solder on the surface of the object to be processed is allowed to flow down naturally. In that case, when the electronic component is transferred horizontally, Although it has the advantage that the contact time of the electronic component to the solder jet can be lengthened by increasing the length of the ejection port, the solder accumulates at the upper end surface of the element such as the rectangular resistor Therefore, the removal of the excess solder may be incomplete. Therefore, conventionally, in order to promote the flow-down of the excess solder, the electronic component is transferred from the lower side to the upper side along the direction inclined with respect to the horizontal plane.

However, in this inclined transfer method, the electronic component can be immersed only in a part of the solder jet ejected from the ejection port, and the distance that the electronic component passes through the solder jet is short. The adhesion may be incomplete. On the other hand, when the configuration of claim 2 in the present application is applied to soldering of electronic components, the excess solder remaining on the surface of the electronic components can be removed even when the electronic components are transferred horizontally. Since it can be forcibly removed by the inert gas ejected from the nozzle, excess solder can be reliably removed under the condition that insufficient adhesion of solder is prevented. It is possible to suppress the surface tension that occurs when the solder that adheres to the surface of the electronic component, and further, it is possible to more reliably prevent the oxidation of the solder, and as a result, it is possible to prevent the electronic component due to poor soldering. This has the effect of significantly reducing manufacturing defects.

[0012]

Embodiments of the present invention will now be described with reference to the drawings (FIGS. 1 to 1).
A description will be given based on 1). In the figure, reference numeral 1 indicates a solder bath formed in a closed box shape, one end of the solder bath 1 is opened upward, and this is covered with a box-shaped cover body 2.
The solder bath 1 is provided with a spout 3 that spouts molten solder upward at a position below the cover body 2 in the solder bath 1.
Is provided so as to extend along the short side direction of the solder bath (see FIG. 5), and the flow path 4 extending toward the other end of the solder bath 1 is connected to the lower surface of the jet port 3 (see FIG. 3). Inside the end of the passage 4, an impeller 6 having a rotating shaft 5 protruding upward is arranged,
The molten solder C is ejected from the ejection port 3 by the rotation of the impeller 6.

The rotary shaft 6 of the impeller 5 is directly driven by a motor or is driven via a power transmission means such as a belt. An appropriate number of straightening vanes 7 having a large number of small holes are provided inside the ejection port 3 so that the molten solder C is ejected from the ejection port 3 in a uniform state. In this case, as shown in FIG. 6, if the small holes of the straightening vanes 7 that are vertically adjacent to each other are arranged in a staggered manner without the small holes of the straightening vanes 7 overlapping in a plan view, the molten solder C is dispersed. Therefore, there is an advantage that the rectification effect can be improved.

At the other end of the solder bath 1, an impeller 6 is provided.
Nitrogen gas is supplied into the solder bath 1 in order to prevent air from entering through the hole through which the rotary shaft 5 penetrates and to prevent the molten solder C in the solder bath 1 from being oxidized. The hose 8 is connected. A fixed type transfer rail 9 as a transfer means for transferring the lead frames B to which the electronic parts A are attached at appropriate intervals penetrates through the cover body 2, and the transfer rail 9 extends in the longitudinal direction of the ejection port 3. The electronic component A, which is horizontally arranged so as to extend along the direction and fixed to the lead portion B1 of the lead frame B, is
It is designed to pass through the solder jet flow ejected from. The upper surface of the cover body 2 is formed of a transparent plate 10 such as glass.

A pair of left and right outlets 11 opening toward the upper portion of the jet outlet 3 are formed in the cover body 2 on both left and right sides of the transport rail 9 so as to extend along the longitudinal direction of the jet outlet 3. Both outlets 11
A hose 12 that supplies nitrogen gas as an example of an inert gas is connected to the. In this case, a rectifying filter 13 made of a porous material such as a sintered metal or a wire mesh filter material is provided in the middle of the blowout port 11 so as to extend over the entire length, and the nitrogen gas has a direction and a flow velocity. The air is blown out from the air outlet 11 in a uniform laminar flow state.

Further, as shown in FIG. 5, the nitrogen gas blowout port 11 is arranged slightly offset from the ejection port 3 toward the front side in the transfer direction so that the electronic component A is immersed in the solder jet. The inert atmosphere starts from the front part. On the upper surface of the cover body 2, a pair of left and right air curtain hoses 11a for ejecting nitrogen gas are connected to the inlet part and the outlet part of the electronic component A, respectively. By ejecting nitrogen gas from the outlet 11a and forming curtains of nitrogen gas on the front and rear sides of the cover body 2 sandwiching the ejection port 3, air from both front and rear openings 14 of the cover body 2 is formed. I try to prevent the invasion of. Discharge holes 11b for discharging the nitrogen gas ejected into the cover body 2 are formed at both front and rear ends of the left and right side plates of the cover body 2.

In order to take measures when trouble occurs,
The entire solder bath 1 is configured to move up and down by an appropriate size, and in order to prevent the nitrogen gas from escaping from the opening 14 of the cover body 2 when the solder bath 1 descends, a cover body is formed. Shutters 16 are provided on both end surfaces of 2 via guides 15 so as to be movable up and down. The shutters 16 are in contact with the upper surface of the transport rail 9, and the openings 16 are closed by the shutters 16. 1 is moved up and down.

The element C of the electronic component A that has passed through the solder jet on the side surface of the portion of the transport rail 9 located in the cover body 2 that is located near the outlet of the electronic component A.
A nozzle 18 is provided so that the nitrogen gas is jetted obliquely from above toward one side to which 1 is attached. In this case, the angle θ formed by the nozzle 18 with respect to the horizontal plane H is preferably about 60 degrees. Further, the temperature of the nitrogen gas ejected from the nozzle 18 is 100 to 20 in order to prevent the solder from being rapidly cooled.
It is preferable to maintain the temperature at about 0 ° C.

In the above-mentioned structure, the electronic component A is transferred during the continuous transfer of the electronic component A along the transport rail 9.
Soldering is performed by passing through the inside of the solder jet flow ejected from the ejection port 3. In that case, since the periphery of the solder jet is kept in an inert atmosphere by the nitrogen gas blown from both the left and right outlets 11, continuous soldering can be performed without being affected by oxidation.

Further, since the electronic component A is horizontally transported, the electronic component A can be immersed in the solder jet for a long time, and soldering failure due to insufficient solder can be prevented, while the electronic component A is horizontally transported. Due to the element C
Even if the solder tends to be excessively attached to the upper end surface of No. 1, the excessively attached solder is blown off by the nitrogen gas ejected from the nozzle 17, thus preventing the solder from becoming insufficient or sticking too much. It is possible to solder in the state.

When the nitrogen gas is blown out through the rectifying filter 13 as in the embodiment, the nitrogen gas hits the solder jet in a laminar state, and therefore the nitrogen gas is blown directly toward the solder jet. However, the surface of the solder jet does not undulate, and therefore, there is an advantage that it is possible to prevent the solder from scattering and adhering to the extra portion. It should be noted that the electronic component A is preheated to about 200 ° C. in advance in a portion before entering the cover body 2 to prevent heat shock due to contact with solder.

The above embodiment was applied to the electronic component A in which the element C1 is mounted on one side of the substrate, but when the element C1 is mounted on both sides of the substrate, as shown in FIG. The nozzles 17 are provided on both sides of the transfer path for the electronic component A.
It is needless to say that it is only necessary to provide the above and to inject an inert gas such as nitrogen gas toward both sides of the electronic component A.

Needless to say, the present invention can also be applied to a soldering device in which electronic components are transported along a direction inclined with respect to a horizontal plane.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an embodiment of the present invention.

FIG. 2 is a perspective view of a main part.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged view of a main part of FIG.

5 is a sectional view taken along line VV of FIG.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is an enlarged view of a current plate provided inside the ejection port.

FIG. 8 is a diagram showing an operation.

FIG. 9 is a perspective view of an end portion of the cover body.

10 is a sectional view taken along line XX of FIG.

FIG. 11 is a partial perspective view of the inside of the cover body on the outlet side of the electronic component.

FIG. 12 is a diagram showing another example of the arrangement of nozzles.

FIG. 13 is a diagram showing a conventional example.

FIG. 14 is a diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solder bath 2 Cover body 3 Jet port 9 Conveyor rail 11 Blowout port 13 Straightening filter 18 Nozzle A Electronic component B Lead frame C Molten solder

Claims (2)

[Claims] 1. A solder bath provided with an ejection port for ejecting molten solder upward, and a transfer means for continuously transferring an object to be processed. In a jet-type soldering device provided so as to pass through a jet flow, in the vicinity of the jet port, on both sides of the transfer path of the object to be processed, the solder jet jetted from the jet port is directed. A jet-type soldering device, which is provided with a blow-out port for blowing out an inert gas such as nitrogen gas. 2. A nozzle according to claim 1, wherein an inert gas such as nitrogen gas is jetted from above toward the surface of the object to be processed after passing through the solder jet. Characteristic jet type soldering device.