JPH0820853A - Solder coating device - Google Patents

Abstract

PURPOSE:To form a uniform solder film in a good state. CONSTITUTION:A solder coating device in which a block 9 set in molten solder is provided with a passage 10 passing a lead 8, a jet pore jetting molten solder jets to the passage is opened, the block is provided with an inert gas feeding pore 20 feeding an inert gas to the outlet side of the passage, the lower side of the passage is provided with a fluidizing member 14 in which both sides are formed of slopes, a jet pare is opened at the center of the fluidizing member and the progressing side of a clamping device 21 holding the lead is mounted with a scraper 23 applying flux every time is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder coating device.

[0002]

2. Description of the Related Art In a conventional apparatus of this type, as shown in FIGS. 5 and 6, a solder oxide 3 retained on the surface of a molten solder 2 stored in a solder bath 1 is moved from a left side to a right side of a plate 4. After removing and storing in the storage chamber 5 provided on the side wall of the solder bath 1, the lead 8 of the semiconductor product 7 held by the lifting device 6 is dipped in the molten solder 2 to form a solder coating on the surface of the lead 8. Was supposed to form.

[0003]

However, it is not possible to completely prevent the oxide from adhering to the leads only by removing the solder oxide on the liquid surface of the molten solder by the plate 4. Also, since the work is normally performed in the atmosphere, the viscosity of the molten solder increases due to the influence of the oxidized molten solder, and when the lead is pulled up from the molten solder, the molten solder adhering to the lead does not drip smoothly. Figure 7
The state becomes as shown in.

That is, as shown in (b) of the lead 8 as shown in FIG. 7 (a), the molten solder becomes thicker at the tip of the lead, and the bridge A is apt to occur, and as shown in (c). The flicker B is likely to be generated, and the thick solder coating C is likely to be generated as shown in (d). When the solder coating locally thickens at the tip of the lead, not only the appearance of the lead is deteriorated but also a problem occurs when the lead is inserted into the printed board.

Therefore, in the present invention, there is provided a solder coating apparatus capable of preventing the adhesion of oxides, icicles, bridges, etc. generated on the leads during solder adhesion and always forming a uniform solder coating in a good condition. The purpose is to provide.

[0006]

In order to solve the above-mentioned problems, the present invention provides a block through which a lead is passed in a block installed in molten solder, and a jet hole for ejecting a molten solder jet is provided in the passage. An open solder coating device is constructed.

Further, a block is provided with an inert gas supply hole for supplying an inert gas to the exit side of the passage, a flow member having inclined surfaces on both sides is provided below the passage, and a jet flow is provided at the center of the flow member. A solder coating device is provided in which a hole is opened and a scraper that applies flux each time is attached to the advancing side of a clamp device that holds a lead.

[0008]

The present invention is configured as described above. The molten solder jet is jetted from the jet holes provided in the flow member in the passage of the block, and the dropped molten solder jet is directed along the inclined surface toward the solder bath wall side. Fluidized to move the dross to the solder bath wall side, pass through the scraper coated with flux in the molten solder jet, and pass the lead through the molten solder jet with the oxide removed to form a solder coating. To do.

[0009]

Embodiments of the present invention will be described in detail with reference to FIGS. The molten solder 2 is contained in the solder bath 1,
A block 9 partially immersed in the molten solder 2 is installed in the molten solder 2. As shown in FIGS. 2 and 4, the block 9 is provided with guide members 11 and 11 ′ facing each other so as to form a passage 10 through which the lead 8 passes, the lower end thereof is cut out to widen the width, and the inclined surfaces 12 are formed on both sides. 12 'forms a fluid member 14 whose center is formed by a horizontal surface 13.

The jet holes 1 are formed on the horizontal surface 13 of the flow member 14.
5, the jet hole 15 is communicated with the inlet 17 of the supply member 16 formed on the lower surface of the block 9, and the inlet 17 is communicated with the molten solder supply device 18 shown in FIG. 1 to melt the molten solder 2. It is designed to be ejected as a solder jet flow 19. Further, an inert gas supply hole 20 is provided on the lead advancing side of one guide member 11 '.

The semiconductor product 7 provided with the leads 8 is held by a clamp device 21. That is, the clamp device 2
The first holding member 22, 22 'holds the upper part of the semiconductor product 7, and one of the holding members 22' has a scraper 23 having flux applied to the tip (on the traveling direction side).
Is fixed, and the movement of the clamp device 21 is controlled by the control device 24.

A heater 25 is installed in the molten solder 2 to constantly heat the molten solder 2 to a set temperature, and a dross receiving box 26 is provided on the peripheral surface of the side wall of the solder bath 1 to generate dross 27. It is designed to put in.

This embodiment is constructed as described above,
The molten solder 2 supplied from the molten solder supply device 18 flows from the inflow port 17 through the jet hole 15 to the molten solder jet 19
And jetted out, and the inclined surfaces 12, 12 ′ of the flow member 14
Along the surface of the molten solder, and collects the dross 27 at a position away from the block 9.

On the other hand, the scraper 23 provided on the clamp device 21 is coated with flux in advance, and the control device 24 moves the clamp device 21 to pass the lead 8 through the molten solder jet 19. At this time, the flux applied to the scraper 23 causes the oxide on the surface of the molten solder jet 19 to flow down to the liquid surface of the molten solder 2 in the solder bath 1, and the molten solder jet 19 is kept in the oxide-free state during the lead operation. 8 is introduced into the molten solder jet 19 to form a solder coating on the leads 8 without oxide adhesion.

The inert gas supply hole 20 provided in the block 9 ejects an inert gas which is set to a temperature slightly higher than the temperature of the molten solder 2 in the solder bath 1 so that the oxygen concentration at the outlet of the block 9 is increased. To prevent the solder coating, icicles, and bridges locally thickening at the tip of the lead, and to form a good and uniform solder coating on the lead 8.

Further, by the inclined surfaces 12 and 12 'of the flow member 14 provided in the block 9, the molten solder jet and the dross 26 generated at the time of solder coating are collected in the vicinity of the dross receiving box 25 provided in the solder tank 1. It is easy to clean and allows easy maintenance of the device.

[0017]

The present invention is constructed as described above,
The surface of the molten solder jet is difficult to oxidize, and variations in the thickness of the solder coating formed on the leads and locally thick solder coating at the tip of the lead, icicles, and bridges are prevented, and the dross moves to a position away from the block. As a result, a uniform solder coating can be formed with good leads. Further, the dross can be easily removed, and the maintenance is easy. Furthermore, continuous processing is possible and high quality production can be performed.

[0018]

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of an embodiment of a solder coating apparatus according to the present invention.

FIG. 2 is a perspective view of a block portion.

FIG. 3 is a partially cutaway perspective view showing a relationship between a block and a clamp device.

FIG. 4 is a sectional view of a block.

FIG. 5 is a cross-sectional view of a conventional device before lead insertion.

FIG. 6 is a cross-sectional view of a conventional device during coating.

FIG. 7 is an explanatory diagram showing the relationship between the leads and the solder coating.

[Explanation of symbols]

 1 Solder Tank 2 Molten Solder 3 Solder Oxide 4 Plate 5 Storage Room 6 Lifting Device 7 Semiconductor Product 8 Lead 9 Block 10 Passage 11 Guide Member 11 'Guide Member 12 Inclined Surface 12' Inclined Surface 13 Horizontal Surface 14 Flowing Member 15 Jet Hole 16 Supply member 17 Inlet 18 Molten solder supply device 19 Molten solder jet 20 Inert gas supply hole 21 Clamping device 22 Clamping member 22 'Clamping member 23 Scraper 24 Control member 25 Heater 26 Dross receiving box 27 Dross A bridge B Turara C Thick solder Film

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 23/50 E

Claims (4)

[Claims] 1. A solder coating apparatus characterized in that a passage for passing a lead is provided in a block installed in molten solder, and a jet hole for ejecting a molten solder jet is opened in the passage. 2. The solder coating apparatus according to claim 1, wherein the block is provided with an inert gas supply hole for supplying an inert gas to the outlet side of the passage. 3. The solder coating according to claim 1, wherein a fluid member having inclined surfaces on both sides is provided below the passage, and a jet hole is opened in the center of the fluid member. apparatus. 4. The solder coating apparatus according to claim 1, wherein a scraper for applying flux each time is attached to the advancing side of the clamp device for holding the lead.