JPH071115A - Automatic continuous soldering device and method for controlling feeding speed of thread solder - Google Patents

Abstract

PURPOSE:To realize an automatic soldering of high quality by supporting the wt. of a soldering iron with a spring connecting the one end with at least one piece of arm in the balancing condition. CONSTITUTION:While slidingly shifting the iron tip of the soldering iron 41 supported so as to be vertically movable along the setting course, plural soldering spots on the path are continuously soldered. Then the soldering iron 41 is hung through two pieces of arms 30, 31 forming double-lever mechanism. This double-lever mechanism is set so as to vertically move the iron tip 44 in the almost perpendicular directuion by shaking the soldering iron 41 held by the arms 30, 31 at almost the same quantity in the reverse direction at the time of shaking the arms 30, 31. Then the wt. of the soldering iron 41 is supported by the spring 32 connecting the one end with at least one piece 31 of arm in the balancing condition. By this method, the generation of the defective soldered position and the soldered bridge can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to soldered parts arranged on a printed wiring board at equal or unequal pitches.
For example, by automatically sliding the tip of a soldering iron tip on a printed wiring board, the lead end of a flat package type IC or a connector having multi-pole leads with a small pitch can be used for continuous soldering. The present invention relates to a soldering device and a method for controlling a feed speed of a yarn solder feeding device provided in the device.

[0002]

2. Description of the Related Art A thread solder is used as a solder, and the solder tip is continuously fed while sliding along a straight line or a curve while the tip of the soldering iron is in contact with a printed wiring board. Japanese Patent Laid-Open No. 62-292264 discloses an automatic continuous soldering device for soldering soldering points one after another by arranging them at equal pitches or unequal pitches on the moving path of the tip. It is known.

In the automatic continuous soldering apparatus for soldering by such a method, the tip moves along the surface having a difference in height between the portion where the lead wire to be soldered exists and the portion where the lead wire does not exist. Therefore, it is necessary to support the soldering iron with a structure in which the pressing force of the tip on the printed wiring board is constant and the tip can move up and down smoothly according to the height difference of the surface. Moreover, it is necessary to continuously supply an appropriate amount of thread solder corresponding to the moving speed of the iron tip to the iron tip.

In the apparatus disclosed in the above publication, a soldering iron held obliquely is supported swingably around a fulcrum pin in the horizontal direction, and a spring applies a biasing force around the fulcrum pin to the soldering iron. By doing so, the pressing force of the iron tip on the printed wiring board is set, and the solder iron swings around the pin to move the iron tip up and down.

Further, in this type of automatic continuous soldering apparatus, the tip is moved by a robot capable of controlling the position and the moving speed of the tip by servo control. By driving with a motor and setting the rotation speed of this variable speed motor to a speed corresponding to the moving speed of the iron tip, the thread solder is continuously supplied to the iron tip.

[0006]

However, in the conventional device in which the soldering iron is swung around the fulcrum pin to move the tip up and down, the printed wiring board may be warped or the lead wire to be soldered may be lifted. When the amplitude of the vertical movement of the tip increases, the angle of the tip with respect to the soldering surface, the pressing force, and the moving position change significantly, which may result in improper soldering or a solder bridge. There was a problem. Further, in the supply of the thread solder in the conventional device, the supply speed of the thread solder to the tip is always constant from the movement start point of the tip to the movement end point, and the tip is melted at the beginning of the movement. There is a problem that soldering defects are likely to occur because the solder is not sufficiently accumulated, and a large amount of molten solder is accumulated on the tip at the end of the movement to easily cause a solder bridge.

The present invention has been made in order to solve the above-mentioned problems of the prior art. Even when the tip has a large amplitude vertical movement, the change in the tip angle and the pressing force is small. Also, it is possible to adjust the amount of molten solder on the tip during sliding movement to an appropriate amount, and with these, highly reliable soldering can be performed without producing unsoldered parts or solder bridges. The problem is to obtain a continuous soldering device.

[0008]

SUMMARY OF THE INVENTION An automatic continuous soldering apparatus according to the present invention is arranged so that a soldering iron tip 41 of a soldering iron 41, which is vertically movable, is slidably moved along a preset path on the soldering iron tip 41. In an automatic continuous soldering apparatus for continuously soldering a large number of arranged soldering points, a soldering iron 41 has two arms 30 and 3 forming a double lever mechanism.
1. The soldering iron 41 suspended by the arms 1 and held by these arms when these arms 30 and 31 swing.
Is oscillated in the opposite direction by substantially the same amount to vertically move the tip 44 in a substantially vertical direction, and at least one of the arms 3
The weight of the soldering iron 41 is supported in a balanced state by a spring 32 having one end connected to 1.

Further, in the method for controlling the feed rate of the thread solder according to the present invention, the tip 44 of the soldering iron 41 is slid and moved along the set route from the soldering start point to the soldering end point. Feed rate of the thread solder in the automatic continuous soldering device for continuously supplying the solder tip 7 to the soldering tip 44 during the period and continuously soldering a large number of soldering points arranged on the above path. In the control method,
One soldering operation from the soldering start point P ₀ to the soldering end point P ₁ is divided into a plurality of sections, and for each section, the thread solder sent while the tip 44 moves through the section. Set the feed length ratio SLP and / or set the tip 44 for each segment relative to the time required for the tip 44 to move from the soldering start point P ₀ to the soldering end point P _1.
The moving time ratio RAT is set.

[0010]

The automatic continuous soldering device having the soldering iron 41 supported by the above-described structure moves up substantially vertically when the tip 44 of the soldering iron is pushed up from the printed wiring board. Even when the tip is moved up and down largely due to the lifting of the lead end to be soldered, the tip 44 does not move in the moving direction, that is, the direction in which it approaches and separates from the adjacent soldering point, and it also moves up and down. Since the change in the angle of the tip 44 and the pressing force accompanying the change are small, the occurrence of defective soldering or solder bridge is greatly reduced in soldering where the tip slides across multiple soldering positions. Can be made.

Further, according to the method for controlling the feed rate of the thread solder of the present invention, the feeding rate of the thread solder to the soldering iron tip 44 moving on the printed wiring board at a constant speed is set at the initial stage of soldering and the final stage of soldering. It can be changed depending on the number of soldering points along the path of the soldering tip, and when soldering the soldering tip that slides across multiple soldering positions. The occurrence of defects and solder bridges can be greatly reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below. FIG. 3 is an overall perspective view of the automatic continuous soldering apparatus. The soldering unit 1 is mounted on the tip of an arm 3 of a Cartesian coordinate system robot 55 so as to be rotatable about a vertical axis. Robot 5
Reference numeral 5 is a first horizontal guide (X-axis direction) 5 of the base 2.
6 includes a column 4 that moves along a column 6, and the column 4 includes a lifting block 57 that moves up and down along a vertical (Z-axis direction) guide (not shown). The arm 3 is orthogonal to the guide 56 of the base. It is supported by an elevating block 57 so as to be movable along a horizontal (Y-axis direction) guide 58, and the solder is moved by moving and elevating these members by a servomotor controlled by an NC controller. The movement start position and movement end position of the iron tip 44 of the iron 41, and the movement locus and movement speed are accurately controlled.

4 and 5 are a partially cutaway side view and a front view of the soldered unit 1, respectively. The soldering unit 1 is attached to the tip of the arm 3 of the robot 55 by a vertical swivel shaft 5, and a yarn solder feeder 6 is provided in a swivel housing 61 which is substantially integrated with the swivel shaft 5. A solder reel 8 is mounted on the back surface of the swivel housing 61, and the thread solder 7 wound around the solder reel 8 is mounted.
Is fed into the yarn solder feeding device 6 through the inlet nozzle 9, and is nipped by the feeding roller 11 and fed. The sent-out thread solder 7 passes through the outlet nozzle 10 and is guided by the solder guide tube 40 to reach the tip 4 of the soldering iron 41.
4 is supplied.

The swivel housing 61 is driven by the motor support 19.
The rotation of the DC motor 13 mounted on the base 21 is reduced by a reduction gear composed of a pinion 14 and a wheel 15, and transmitted to a drive gear 16 fixed to the shaft of the solder feed roller 11 via an intermediate gear 17. . The feed roller 11 has a structure in which the thread solder 7 is sandwiched between a pair of rollers provided with knurls, and the thread solder 7 is fed out by the rotation of the rollers 11, and the meshing gap of the pair of rollers 11 is adjusted by a meshing adjuster 18 The rotation speed of the roller 11 (and hence the feed speed of the thread solder) is adjusted by controlling the rotation speed of the DC motor 13.

Below the base 21 of the swivel housing,
An iron mounting shaft 22 is provided so as to project, and an XY adjustment machine 25 is provided on the iron mounting shaft 22 with a fixing bracket 23.
Is attached. The XY adjuster 25 has two sliders that slide in mutually orthogonal directions.
By moving these sliders with an adjusting screw, the tip 44 is adjusted so as to be located on the central axis of the turning shaft 5.

An arm support bracket 29 is fixed below the XY adjuster 25 via a joint block 26. A main arm 31 and an auxiliary arm 30 are pivotally supported on the arm support bracket 29 by bearing pins 48 and 49, and a trowel holding bracket 34 is connected to the tips of these arms 31, 30 via bearing pins 50, 51. There is. The iron holding bracket 34 holds the base end of the soldering iron 41 and the tip 4 of the soldering iron 41.
4 is located obliquely below the iron holding bracket 34. The main arm 31 and the auxiliary arm 30 constitute a double lever mechanism of a four-bar linkage mechanism, and the arms 30, 31 and a soldering iron 41 extending obliquely therebelow are similar to a beam mechanism of a horizontal retracting crane. The tip 44 is moved up and down substantially vertically by swinging the arms 31 and 30.

A stopper plate 35 is attached to the iron holding bracket 34, and an angle of a tip 44 of a soldering iron 41 held by the iron holding bracket 34 is adjusted by an adjusting screw 53 screwed to the stopper plate 35. C can be adjusted. A screw bracket 45 is provided on both sides in the middle of the main arm 31, and a tension bolt 33 screwed into the screw bracket 45 and a bearing pin 49 on the arm support bracket side of the auxiliary arm 30.
A tension spring 32 is stretched between the tension spring 32 and the tension spring 32. The tension spring 32 balances the weight of the soldering iron 41, and the tension bolt 33 is rotated to push the tip 44 against the printed wiring board. The contact force can be adjusted.

Next, a method of controlling the feed rate of the thread solder during the movement of the iron tip will be described. In the conventional automatic continuous soldering apparatus of this type, the soldering iron tip 44 is slid at a constant speed while the thread solder is supplied at a constant speed. That is, the controller starts the soldering start point P ₀ , the soldering end point P ₁ , the soldering iron moving speed V, and the amount of thread solder supply (the length of the soldering iron sent while the soldering iron moves from the start point to the end point). When L) is set, (P ₁ −
The time T required for soldering is calculated by P ₀ ) / P, the supply speed v of the thread solder 7 is calculated by L / T,
A control method has been adopted in which the yarn solder 7 is supplied at a constant speed from the soldering start point to the soldering end point by rotating the DC motor 13 at a speed corresponding to this speed v.

On the other hand, in the apparatus of this embodiment, one soldering operation is divided into four sections, and for each section, the ratio RAT of the time belonging to that section and the ratio S of the feed length of the thread solder S
LP can be set, and by combining the settings of the time ratio RAT and the length ratio SLP, the yarn solder feed speed can be changed between the sections.

Specifically, the soldering tip is the soldering start point P _0.
From the soldering end point P ₁ to the soldering end point P ₁ by multiplying the feed length ratio SLP ₁ to SLP ₄ (percentage display) of the respective thread solders from the first to the fourth divisions. And dividing by 100 determines the supply length of the thread solder in each of the first to fourth sections.

FIG. 1 shows the first section with a constant time ratio RAT.
Minute to third length ratio SLP ₁Or SLP₃To
When set to 50, 25, 13 (length ratio of the 4th section
SLP_FourWill inevitably be 12. ) Tip movement time
(Horizontal axis; can also be seen as the tip movement distance)
Graph showing the feed length (vertical axis) of the thread solder
2 shows an example of a control program for a car. Ie figure
When the program of 1 is executed, as shown in the graph, 1
0 mm of thread solder is 5 mm in the first section and 2.
5mm, 1.3mm in 3rd section, 1.2mm in 4th section
Send out at a rate of. In this example, the time ratio RAT is constant
So, the time intervals for each segment are equal, so in this example
Means that the feed rate of the thread solder gradually decreases. Figure
The slope of the graph indicates the change in the thread solder supply speed at each point.
Shows.

Further, the soldering time T is calculated from the soldering start point P ₀ , the soldering end point P ₁ and the moving speed V of the tip, and the time ratio RAT ₁ to RAT of each section is calculated at this T.
By multiplying by ₄ (percentage display) and dividing by 100, the time interval for each category can be set.

In FIG. 2, the feed length ratio SLP of the thread solder in each section is fixed and the time ratios RAT ₁ to RAT ₃ in the _{first to} third sections are set to 10, 20, and 50 (fourth section). The time ratio RAT ₄ inevitably becomes 20.) The moving time of the tip in the case (horizontal axis. It can also be regarded as the moving distance of the tip) and the feed length of the thread solder (vertical axis). FIG. 4 is a diagram showing a graph showing a relationship with and a control program example thereof. When the program in Figure 2 is executed,
As shown in the graph, first, while the tip moves a distance of 1/10 of the total movement distance, 1/4 of the total feed amount, that is, 2.5 mm of the thread solder is fed out, and the tip is Next, the same 2.5 mm of thread solder is fed out while moving in a section of one-fifth of the total length, and then, while the tip moves a distance of half of the total length, the thread solder is 2. The time assigned to each section and the solder feed in that section are such that the thread solder is fed out by 5 mm and finally 2.5 mm while the tip moves one-fifth of the total length. The speed changes. The slope of the graph in the figure shows the change in the feed rate of the thread solder at each time point.

In the actual setting work, first, only the length ratio SLP of each segment is set, the soldering work is tried, and the time ratio RAT is set if necessary. It is practical to set In this way, from the soldering start point P ₀ to the soldering end point P
_If the feed amount of the thread solder is changed during the movement of the tip up to ₁ , the feed rate of the thread solder can be increased in the initial stage of movement, for example, and the shortage of molten solder at the tip of the tip can be promptly confirmed. In addition, it is possible to perform good soldering which is uniform as a whole and has no unsoldered portion or solder bridge.

Further, the moving speed of the iron tip and the supply amount of the thread solder can be set in the same manner as the setting work in the conventional apparatus, and the length ratio and the time ratio of each classification are added to the setting work. Therefore, it is possible to perform the setting by using the actual result data of the conventional device.

[0026]

According to the present invention described above, the tip of the solder is slid along the surface of the printed wiring board, and a large number of soldering points arranged on the movement locus are continuously soldered. The occurrence of defective solder spots and the occurrence of solder bridging can be significantly reduced during the process, and thus not only high-quality automatic soldering can be realized, but also stable automatic continuous soldering work becomes possible.
In addition, since it is possible to reliably perform soldering work under bad conditions such as warpage of the printed wiring board and unevenness of the soldered portion, there is an effect that automatic continuous soldering can be performed on a wider range of components. .

[Brief description of drawings]

FIG. 1 is a control program and operation diagram showing a first embodiment of the method of the present invention.

FIG. 2 is a control program and operation diagram showing a second embodiment of the method of the present invention.

FIG. 3 is an overall perspective view showing an embodiment of the device of the present invention.

FIG. 4 is a partially broken side view of a soldered unit portion of the device of the present invention.

FIG. 5 is a partially broken front view of a soldered unit portion of the device of the present invention.

[Explanation of symbols]

 7 Thread solder 30 Auxiliary arm 31 Main arm 32 Extension spring 41 Soldering iron tip 44 Tip

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H05K 3/34 S 7128-4E // B23K 101: 42

Claims (3)

[Claims] 1. A soldering iron (41) movably supported up and down slides a tip (44) of the soldering iron (44) along a set route to continuously connect a number of soldering points arranged on the route. In the automatic continuous soldering device that solders
Two arms (30) with a soldering iron (41) forming a double lever mechanism,
It is suspended via (31), and when both arms (30) and (31) swing, the soldering irons (41) held by these arms have approximately the same amount in opposite directions. It is arranged to swing vertically to move the tip (44) up and down in a substantially vertical direction.
A spring with one end connected to at least one of the arms (31)
The automatic continuous soldering apparatus, wherein the weight of the soldering iron (41) is supported by the balance (32). 2. The soldering iron (41) is slidably moved along a set path from a soldering start point to a soldering end point while the tip (44) of the soldering iron (41) is slid and moved during the movement period. ) Is continuously supplied to the iron tip (44) to continuously solder a large number of soldering points arranged on the above path, in the method for controlling the feed rate of the thread solder in the automatic continuous soldering device. , Soldering start point (P ₀ ) to soldering end point
Divide one soldering operation up to (P ₁ ) into multiple sections,
For each segment, the ratio (SLP) of the feed length of the thread solder sent while the tip (44) moves through the segment is set, Feed rate control method. 3. The thread solder 7 is slidably moved along a set route from the soldering start point to the soldering end point while the soldering iron tip (44) is moving the thread solder 7 during the movement period. In the method for controlling the feed rate of the thread solder in the automatic continuous soldering device, which continuously supplies the tip (44) and continuously solders a large number of soldering points arranged on the path, From the soldering start point (P ₀ ) to the soldering end point (P ₀
The soldering operation up to ₁ ) is divided into a plurality of sections, and the tip (44) moves from the soldering start point (P ₀ ) to the soldering end point (P ₀ ).
Tip for each segment with respect to the time required to move to ₁ )
(44) A method for controlling the feed rate of the thread solder in the automatic continuous soldering apparatus, characterized in that the moving time ratio (RAT) is set.