JPH08288636A - Printed board soldering device - Google Patents

Abstract

PURPOSE: To provide a printed board soldering device which can efficiently supply solder even to a narrow part on a printed board on which parts are mounted at a high packing density and extremely hardly cause insufficient soldering by forming a sharp wave crest which has small difference in ruggedness and is suppressed in vertical and lateral movement in at least the nozzle main body of a first wave. CONSTITUTION: A relatively thick jet plate 17 which closes the opening 16 of a slit structure formed on the upper surface of a nozzle main body B for jetting molten solder is provided to the opening 16 and a relatively deep jetted solder guiding groove 18 is formed along the axial direction at the center on the upper surface of the plate 17. In addition, numerous jetting ports 19 having radii nearly equal to the total width of the groove 18 are formed at appropriate intervals around the ridge lines 18a or the vicinity of the lines 18a of vertical step faces forming the groove 18. At the same time, the ports 19 are arranged zigzag in a plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved soldering apparatus for printed circuit boards.

[0002]

2. Description of the Related Art Conventionally, a first wave nozzle body having a turbulent wave forming plate is provided upstream of a printed circuit board in a solder bath, and a second wave nozzle having a laminar wave forming means is provided downstream thereof. The main bodies are arranged side by side, and the first wave nozzle main body has a thin turbulent wave forming plate 2 attached to the upper end jet port of the first wave nozzle main body 1 as shown in FIG. Forming plate 2
There is known a soldering device in which a large number of ejection holes 3 having a punch plate structure are provided. This device ejects the molten solder in a half-wave shape from the ejection port 3 of the first wave nozzle body 1 to form a large number of wavefronts 4 of the half-wave molten solder as shown in FIG. Based on the flow of the molten solder to the plate 2 by the pressurizing means, the wave front 4 is made to be in a turbulent state and irregularly fluctuates vertically and horizontally so that the molten solder is supplied to the soldering portions of the printed circuit board and the electric component. The first soldering step and re-soldering to the soldering portion of the printed circuit board and the electric component by the first step of soldering by the molten solder of the laminar flow wave forming means or the flat surface dipping means for forming the wave in the laminar flow state. The second soldering step for applying is performed. (For example, Japanese Patent Publication No. 63-1506
(See Publication No. 3)

[0003]

According to the above-described soldering apparatus, the wave crest is made turbulent and is varied vertically and horizontally, so that the solder can be efficiently soldered to a narrow portion of the printed circuit board having a high density of mounted components. Even if it is acknowledged that soldering can be performed with good supply and less soldering defects, there is little guarantee. It is extremely unlikely that the wave front is changed in this way so that the solder is efficiently supplied to a high density portion of the mounted component of the printed circuit board that passes in a short time (2 to 3 seconds). That is, defective soldering occurs when the printed circuit board passes through the lowered crest. Therefore, in order to prevent the occurrence of this soldering failure, it is necessary to provide a wide-area turbulent wave forming plate having a plurality of rows of jet holes. The wide area of the turbulent wave forming plate in this way is inconvenient in designing and manufacturing, because only a short jet wave crest can be obtained, and therefore a larger pressing means than necessary is required for the molten solder.

It is an object of the present invention to form a sharp wave front with a small unevenness difference in at least the first wave nozzle body and a suppressed vertical and horizontal variation, and to solder a narrow portion of a printed circuit board having a high density of mounted components. It is an object of the present invention to provide a device in which soldering is efficiently supplied and in which soldering failure is extremely rare.

[0005]

SUMMARY OF THE INVENTION The structure of the present invention for solving the problems of the prior art has an opening of a slit structure formed on the upper surface of a nozzle body for jetting molten solder, and has a relatively thick wall for closing the opening. Is provided, and a relatively deep jet solder guide groove is formed in the center of the upper surface of the jet plate along the longitudinal axis direction thereof, and the ridge line of the vertical step surface before or after forming the jet solder guide groove or Centered around the ridgeline, and
A large number of jet holes each having a radius of substantially the entire width of the jet solder guide groove are formed at appropriate intervals, and the jet ports in the front and rear rows are arranged in a staggered plane. ,
The upper surface of the nozzle body is mounted on the opening so as to be lower than the upper surface of the nozzle body, and a retaining portion is formed in the upper portion of the jet plate to partially dampen the front-back flow of the solder, and the retaining portion suppresses fluctuation of the jet wave front. By doing so, a plurality of jet plates are installed side by side at the opening of the nozzle body, the jet ports of adjacent jet plates are shifted by one pitch phase, and the jet wave tops formed on the jet plates are The uneven waveform does not overlap the front and back.

[0006]

The jet nozzle provided on the jet plate having a relatively large thickness makes it possible to obtain a jet wave crest with a sharp tip and a higher pressure-melting solder than the ordinary one. A jet solder guide groove is provided in the center of the upper surface of the jet plate, the center of the jet port is set to the ridge line of the vertical step surface forming the jet solder guide groove, or in the vicinity of the ridge line, and the size of the jet nozzle is set to the jet solder. By making the width of the guide groove approximately the same as the radius, the jet wave fronts in each row are integrated, and the vertical and horizontal fluctuations of the jet wave fronts are eliminated, making it possible to efficiently solder the narrow area of the printed circuit board where the mounting components are dense. It is possible to carry out soldering in which the supply of the solder and the occurrence of defective soldering are extremely small. A stagnation part of the molten solder that has a step with the upper surface of the nozzle body is formed on the upper part of the jet plate.This stagnation part damps part of the flow of the jet solder in the front-back direction and suppresses fluctuations in the jet wave front. As a result, a stable jet waveform can be obtained and good soldering can be performed. A plurality of jet plates were installed side by side, and jet ports of adjacent jet plates were shifted by 1 pitch phase so that the corrugated waveform formed at the top of the jet wave front in each row did not overlap in the front and back. As a result, it is possible to form stable jet wave crests in the front and rear rows in the nozzle main body, and further, soldering with less occurrence of soldering failure can be achieved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, details of embodiments of the present invention will be described with reference to the drawings. 1 is an explanatory view of the device of the present invention, FIG. 2 is a vertical sectional side view of a first wave nozzle body, FIG. 3 is a partial front view of the first wave nozzle body, and FIG. 4 is a plan view of a main part of the first wave nozzle body. FIG. 5, FIG. 5 is an enlarged cross-sectional view of the jet plate portion, FIG. 6 is a partially enlarged plan view of the jet plate portion, FIG. 7 is an explanatory diagram showing a jet wave crest upper end waveform, and FIG. 8 is another embodiment in which a plurality of jet plate portions are arranged in parallel. FIG. 9 is a partially enlarged plan view of an example, and FIG. 9 is an explanatory diagram showing a jet wave crest upper end waveform of another embodiment.

FIG. 1 shows an embodiment of the soldering apparatus of the present invention, and the soldering apparatus A for the printed circuit board is constructed as follows. Reference numeral 11 denotes a solder bath, and a printed circuit board (not shown) shown by a virtual line above the solder bath 11.
The transport means 12 is provided. In the solder bath 11, there is a nozzle body B of a first wave for jetting the molten solder 13 on the upstream side of conveyance of the printed circuit board, and the molten solder 1 is on the downstream side thereof.
A second wave nozzle main body C for jetting 3 in a plane laminar waveform is accommodated side by side. In the figure, 14 and 15 are ducts provided with a pressurizing means (not shown) for jetting the molten solder 13 from the nozzle bodies B and C. The printed circuit board soldering apparatus A is generally configured as described above.

The present invention is an improvement of the first wave nozzle body B of the soldering apparatus A, and the details thereof will be described with reference to FIGS. In the opening 16 having a slit structure formed on the upper surface of the nozzle body B through which the molten solder 13 is jetted, a jet plate 17 having a relatively thick wall so as to close the opening 16 is formed.
To provide. A relatively deep jet solder guide groove 18 is formed in the center of the upper surface of the jet plate 17 along the longitudinal axis direction thereof, and the ridge line 18a of the vertical step surface before or after the jet solder guide groove 18 is formed or the ridge line 18a of this ridge line 18a. A large number of jet holes 19 centered in the vicinity and having a radius of substantially the entire width of the jet solder guide groove 18 are formed at appropriate intervals over the entire length of the front and rear ridges 18a, and are arranged in rows in the front and rear. Spout 1
As shown in FIG. 4, 9 are arranged in a staggered plane. In the figure, 20 is a mounting piece for supporting both ends of the jet plate 17, 2
1 is a bolt for fastening.

As is apparent from FIGS. 2 and 5, the upper surface of the jet plate 17 is mounted on the opening 16 so as to be slightly lower than the upper surface of the nozzle body B, and the molten solder 13 is placed on the upper surface of the jet plate 17. A solder retaining portion 22 for partially dampening the longitudinal flow is formed, and the retaining portion 22 suppresses vertical and horizontal fluctuations of the jet wave front 13a.

[0011]

[Description of Operation] The operation will be described based on the embodiment shown in FIGS. 2 to 7 described above. The molten solder 13 that moves up the nozzle body B of the first wave through the duct 14 is as shown in FIG. A jet is jetted upward from each jet port 19. Since the radial portions before and after the jet holes 19 in each row are in the jet solder guide groove 18, as shown by the arrow in FIG. 6, a large amount of jet solder flows in the direction of the jet solder guide groove 18, and the wave fronts in the front row are rearward. The wave crests in the rear row are formed so as to be inclined forward. In combination with this action, the wave fronts formed in the adjacent jet ports 19 are formed in the directions toward each other, and the front ends of the wave fronts are integrated as shown in FIG. 5 and as shown in FIG. In addition, a stable jet wave crest 13a is formed with a slight difference between the concave and convex portions of the wave crest waveform and a sharp tip with little fluctuation in the vertical and horizontal directions.
The jet wave crest 13a efficiently supplies a narrow portion of a printed circuit board having a high density of mounted components, and can perform soldering with extremely few soldering defects.

Next, another embodiment will be described with reference to FIGS. In this embodiment, the jet plate 1 having the same structure as that described above is used.
7 are mounted side by side on the opening 16 of the nozzle body B, and the jet ports 19 of the jet plates 17 adjacent to each other are shifted by one pitch phase so that the concavo-convex waveform formed on the top of each jet wave front 13a is Configure so that they do not overlap. As shown in FIG. 9, a plurality of rows of stable jet wave crests 13a formed in the front-rear direction enables soldering with less soldering failure.

[0013]

As described above, according to the structure of the present invention, the following effects can be obtained. (A) With the jet holes provided in the jet plate having a relatively large thickness, the pressure-melted solder is higher than the usual one, and a jet wave tip with a sharp tip can be obtained. A jet solder guide groove is provided in the center of the upper surface of the jet plate, the center of the jet port is set to the ridge line of the vertical step surface forming the jet solder guide groove, or in the vicinity of the ridge line, and the size of the jet nozzle is set to the jet solder. By making the width of the guide groove approximately the same as the radius, the jet wave fronts in each row are integrated, and the vertical and horizontal fluctuations of the jet wave fronts are eliminated, making it possible to efficiently solder the narrow area of the printed circuit board where the mounting components are dense. It is possible to carry out soldering in which the supply of the solder and the occurrence of defective soldering are extremely small. (B) Since the molten solder stagnation portion having a step with the upper surface of the nozzle body is formed in the upper part of the jet plate, this stagnation portion damps a part of the flow of the jet solder in the front-rear direction, and
It is possible to suppress fluctuations in the jet wave crest, obtain a stable jet waveform, and perform good soldering. (C) A plurality of jet plates are installed side by side and the jet ports of adjacent jet plates are offset by one pitch so that the corrugated waveforms formed at the tops of the jet crests in each row do not overlap in the front and back. With this configuration, it is possible to form a plurality of rows of front and rear stable jet wave crests on the nozzle body, and further, soldering with less occurrence of soldering failure can be achieved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a device of the present invention.

FIG. 2 is a vertical sectional side view of a first wave nozzle body.

FIG. 3 is a partial front view of a first wave nozzle body.

FIG. 4 is a plan view of an essential part of the first nozzle body.

FIG. 5 is an enlarged cross-sectional view of a jet plate portion.

FIG. 6 is a partially enlarged plan view of a jet plate portion.

FIG. 7 is an explanatory diagram showing a waveform of a jet wave crest upper end.

FIG. 8 is a partially enlarged plan view of another embodiment in which a plurality of jet plates are arranged side by side.

FIG. 9 is an explanatory diagram showing a jet wave crest upper end waveform of another embodiment.

FIG. 10 is a partially cutaway perspective view of a conventional nozzle body.

FIG. 11 is a perspective view showing a jet flow waveform in a used state of a conventional example.

[Explanation of symbols]

 A soldering device B first wave nozzle main body C second wave nozzle main body 11 solder bath 12 transport means 13 molten solder 13a jet wave crest 14 duct having pressure applying means 15 duct having pressure applying means 16 opening 17 jet plate 18 jet solder guide groove 18a ridge line 19 jet hole 20 mounting piece 21 bolt 22 retention part

Claims (3)

[Claims] 1. A relatively thick jet plate is provided at an opening of a slit structure formed on the upper surface of a nozzle body for jetting molten solder, and a relatively thick jet plate is provided at the center of the upper surface of the jet plate.
A relatively deep jet solder guide groove is formed along the longitudinal axis direction of the jet solder, and the ridgeline of the vertical step surface before and after the jet solder guide groove is formed or the vicinity of this ridgeline is centered and the jet solder guide groove is substantially A soldering device for a printed circuit board, characterized in that a large number of jet holes each having a full width as a radius are formed at appropriate intervals, and the jet ports in each of the front and rear rows are arranged in a staggered pattern on a plane. 2. The jet plate is mounted on the opening so that the upper surface of the jet plate is lower than the upper surface of the nozzle body, and a retention portion is formed on the upper portion of the jet plate to partially dampen the front-back flow of the solder. The soldering device for a printed circuit board according to claim 1, wherein the staying portion suppresses fluctuation of the jet wave front. 3. A plurality of jet plates are installed side by side at the opening of the nozzle body, and jet ports of adjacent jet plates are shifted by one pitch phase so that the jet crests formed on the jet plates are above the jet wave crests. The soldering device for a printed circuit board according to claim 1, wherein the corrugated waveform does not overlap the front and rear.