JP2002033573A - Jet solder tub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jet solder tub suitable for soldering to a printed circuit board by making narrow and sharp a surface projected by a jet. SOLUTION: This tub is provided with a rear upper plate 8, with which an inner box 20 provided inside an outer box 2 of a solder tub 1 is extended from the upper part of a rear side plate 6 on the rear side in the advancing direction of a printed circuit board PB toward a solder jet port 25, a front upper plate 9 extended from the upper part of a front side plate 7 on the front side in the advancing direction toward the solder jet port 25 and a streamline forming part 20 composed of a sloped plate 22 from the extension side of the front upper plate 9 to the oblique upside and an erected plate 23 almost vertically rising from the sloped plate, the rear side plate 6 is inclined from the lower part in the front oblique upside and formed higher than the front side plate 7, the upper end of the erected plate 23 and the upper surface of the rear upper plate 8 are made into almost same height, and the solder jet port 25 is formed from the side face of the erected plate 23 and the terminal edge of the rear upper plate 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet solder bath for soldering to a printed circuit board, and more particularly to a structure for forming a jet surface of solder.

[0002]

2. Description of the Related Art In manufacturing a printed wiring board, an electronic component is mounted on the surface of a printed circuit board, fixed by soldering and applying an adhesive, and the back surface is then touched by a jet surface in a jet solder bath. The terminal and the like protruding from the back surface are soldered to a printed wiring or the like. FIG. 2 is a sectional view schematically showing a conventional jet solder bath of this type.

In FIG. 1, reference numeral 1 denotes a jet solder bath,
An inner box 3 is provided therein and accommodates the molten solder S.
The middle box 3 is provided with a solder outlet 4 described later on the upper part,
The solder S is circulated by being ejected from the solder ejection port 4 and passing through the lower opening 5 and the left and right outer sides of the middle box 3 in FIG. Above the middle box 3, a swelling surface M is formed by ejecting the solder S. PB is a printed circuit board, which is placed on a belt B and is moved leftward as indicated by an arrow while touching the back surface of the rising surface M in a state of being inclined upward to the left in FIG. Terminals and the like are soldered to a printed wiring or the like.

[0004] The middle box 3 comprises a rear plate 6 on the rear side with respect to the traveling direction of the printed circuit board PB and a front plate 7 on the front side.
A rear upper plate 8 which is curved from the upper portion of the rear plate 6 and extends in the horizontal direction toward the solder outlet 4; and a front upper portion which is extended from the upper portion of the front plate 7 in the horizontal direction toward the solder outlet 4. And a plate 9. A streamline forming part 10 is further provided on the edge side of the front upper plate 9. The streamline forming part 10 is composed of an inclined plate 11 extending obliquely upward, and is attached to the front upper plate 9 so that the distance between the front and rear of the solder outlet 4 can be adjusted.

[0005] The rear side plate 6 is inclined obliquely upward and forward from the lower portion, and is convexly curved upward, and is formed higher than the front side plate 7 together with the upper surface of the rear upper plate 8. The rear upper plate 8 and each edge of the inclined plate 11 have the same height as each other, and the solder outlet 4 is formed by each edge. The height H from the upper surface of the front upper plate 9 to the edge thereof is set to about 20 mm, and the horizontal length L1 from the edge of the front upper plate 9 is about 25 mm to 25 mm. 3
5 mm, the opening width L2 of the solder ejection port 4 is about 30 mm
To 40 mm.

In the above configuration, the molten solder S
Are supplied from the lower opening 5 into the inner box 3 and
And a raised surface M is formed on the upper side. In order to make the surface of the swelling surface M smooth, the width of the solder ejection port 4 is set to be relatively large, so that the width of the swelling surface M in the front-rear direction is relatively large. As shown in the figure, the printed circuit board PB is moved in the direction of the arrow while touching the back surface of the printed circuit board PB, and the components provided on the back surface are soldered.

[0007]

However, in the above-mentioned jet solder bath, if the width of the solder jet port 4 is made too small,
Since the solder flow upward in the middle box 3 is disturbed near the solder ejection port 4 and the shape of the swelling surface M is disturbed, the width of the solder ejection port 4 is inevitably set to be wide, so that the width of the swelling surface M is increased. Is relatively wide. As a result, the printed circuit board P
B has been immersed in the jet solder for a long time, and the mounted component may be overheated and deteriorated. In addition, since the separation angle α when the solder S is separated from the back surface of the printed circuit board PB at the front portion A of the raised surface M is relatively small, there is a possibility that a bridge may be formed on the soldering surface.

In order to solve the above-mentioned problems, the present invention provides a jet solder bath suitable for soldering to a printed circuit board PB by making the width of a swelling surface caused by the jet narrow and steep. Aim.

[0009]

In order to achieve the above object,
The invention according to claim 1 is a rear upper plate in which the inner box provided in the outer box of the solder bath extends from the upper portion of the rear plate on the rear side with respect to the traveling direction of the printed circuit board toward the solder ejection port. When,
An inclined plate comprising a front upper plate extending from the upper part of the front plate on the front side with respect to the traveling direction toward the solder ejection port, and an oblique plate extending obliquely upward from the extension side of the front upper plate; The rear plate is formed higher than the front plate by inclining forward and obliquely upward from the lower part, and the upper end of the standing plate and the rear upper plate are provided. The height of the upper surface was almost the same as that of the upper surface, and the side surface of the standing plate and the edge of the rear upper plate formed a solder ejection port.

[0010] In the jet solder bath, the molten solder is jetted from the solder jet port. In the solder jet port, the molten solder flows along the standing plate at the front side in the advancing direction and the upper portion of the solder jet port. On the front side, the ejected solder flows downward along the standing plate and flows along the inclined plate.

According to a second aspect of the present invention, the streamline forming portion formed by the inclined plate and the upright plate is attached to the front upper plate so as to be able to adjust the distance before and after the jet port, and the solder is formed by the adjustment. The width of the raised surface is adjusted.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view schematically showing a jet solder bath as an embodiment of the present invention. In this figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

Reference numeral 20 denotes a middle box, and its respective parts 5 to 9 are constructed in the same manner as in FIG. Reference numeral 21 denotes a streamline forming portion, which is an inclined portion (inclined plate) 22 extending obliquely upward from the edge side of the front upper plate 9 and an upright portion (standing plate) 23 extended from the inclined portion 22 in the vertical direction. And a solder outlet 25 described later.
Are attached by bolts 24 so that the front and rear intervals can be adjusted.

The streamline forming section 21 regulates the streamline of the solder S by the surface of each section, and the upper end of the upright plate 23 is formed to have almost the same height as the upper surface of the rear upper plate 8.
Then, the inclined plate 22 has its inclined extended end side curved to be substantially horizontal, and is integrated with the lower end of the standing plate 23. The upright plate 23 is formed such that its upper end has the same height as the upper surface of the rear upper plate 8, and a side surface thereof and an edge of the rear upper plate 8 form a solder outlet 25. The intervals between the solder jet ports 25 are adjusted by moving and adjusting the streamline forming section 21 back and forth.

In the streamline forming portion 21 in this example, the height H1 of the standing plate 23 is set to about 10 mm, and the inclination of the inclined plate 22 is made gentler than that in FIG.
The horizontal length L1 from the edge of the front upper plate 9 is set to about 4
The opening width L of the solder ejection port 25 is set to 5 mm to 55 mm.
2 is adjusted to about 10 mm to 20 mm.

In the configuration shown in FIG. 1, the molten solder S is jetted from the solder jet port 25, and a raised surface M is formed on the upper side thereof. The solder outlet 25 is provided on the standing plate 2.
3, the gap is relatively narrow and extends in the vertical direction, so that the solder S is accelerated in the vertical direction at a high speed and ejected. The ejected solder S descends sharply along the standing plate 23 and then flows along the inclined plate 22, so that the width of the swelling surface M by the jet flow is narrow and steep. Then, the separation angle α of the solder S at the front portion A of the swelling surface M becomes relatively large. Therefore, the contact width with the printed circuit board PB is reduced, the heating time is shortened, the components are prevented from being deteriorated, and there is no possibility that a bridge is formed on the soldering surface.

[0017]

According to the first aspect of the present invention, the middle box provided in the outer box of the solder bath is inclined obliquely upward toward the front upper plate on the front side with respect to the traveling direction of the printed circuit board. A streamline forming part comprising a plate and an upright plate rising substantially vertically from the inclined plate, and having a height substantially equal to the upper surface of the upright plate and the upper surface of a rear upper plate at the rear side, Since the solder ejection port was formed by the side surface and the edge of the rear upper plate, the solder was ejected by being accelerated in the vertical direction and steeply descending along the standing plate,
It flows along the inclined plate. Therefore, the width of the raised surface due to the jet becomes narrower and steeper, and when the solder is separated from the back surface of the printed circuit board at the forward portion of the raised surface, the separation angle at the separation point becomes relatively large, and the printed circuit board becomes larger. And the heating time is reduced, and the deterioration of the parts is prevented.

According to the second aspect of the present invention, the streamline forming portion according to the first aspect is attached to the front upper plate, and the interval between the front and rear of the solder outlet can be adjusted by the attachment. The contact width can be appropriately adjusted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a jet solder bath as an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a conventional jet solder bath.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 jet solder tank 2 outer case 5 lower opening 6 rear side plate 7 front side plate 8 rear upper plate 20 middle box 21 streamline forming portion 22 inclined portion (inclined plate) 23 standing portion (standing plate) 25 soldering port PB Printed circuit board S Solder M Swell surface

Claims (2)

[Claims] 1. An outer box having an inner box formed therein.
Molten solder is ejected from a solder ejection port provided at the upper part of the middle box, circulated through the outside of the middle box to form a swelled jet surface by the squirt, and soldered to a printed circuit board moving on the jet surface. In the jet solder bath to be performed, the middle box is curved from an upper portion of a rear plate on the rear side with respect to the traveling direction of the printed circuit board, and is extended substantially horizontally toward the solder ejection port. A front upper plate extending in a substantially horizontal direction from an upper portion of the front side plate on the front side with respect to the direction toward the solder ejection port, and an inclined plate which is inclined obliquely upward from the extension side of the front upper plate. A streamline forming portion is provided by a standing plate that rises substantially vertically from the inclined plate, and the rear plate is inclined obliquely upward and forward from below, and is higher than the front plate together with the upper surface of the rear upper plate. Formed at the upper end of the upright plate Rear upper plate is the upper surface and formed in the substantially the same height, to form a solder ejection port in the side surface and the rear upper edge of the standing up plate, the jet solder bath, characterized in that. 2. The jet solder bath according to claim 1, wherein the stream line forming portion is attached to a front upper plate so as to be able to adjust a distance before and after the solder jet port.