JPS6160597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a covered wire welding device, and more particularly to a device for forming a solder layer on a conductive pattern and melting the solder layer to join the covered wire to the conductive pattern.

Due to the miniaturization and increased density of electronic components, high reliability of micro welding technology is desired. In addition, electronic components often use conductors made of bare copper wire coated with an insulating material such as polyurethane resin or nylon resin. It is necessary to connect the patterns by forming a solder layer.

To connect a covered wire to a conductive pattern, first remove the covering of the covered wire using a mechanical or chemical method, and then connect using a soldering iron or resistance welding method, or heat the connection point with a heater electrode to insulate it. After the coating is melted or evaporated, a welding current is passed between the heater electrode and the cold electrode to melt the two materials.

Each of the conventional connection methods will be explained below.

(1) In the method using a soldering iron, the cost of equipment is low, but as mentioned above, the covering of the covered wire is removed before soldering, which increases the working time. Further, even if the tip of the iron is small, it is approximately 4 mm ² , and if the tip is too small, the life of the tip will be shortened and the amount of heat will be reduced.

(2) Resistance welding involves passing a large current through the joint and melting the metal using the converted Joule heat. is not possible.

(3) In the method of using both a heater electrode and a cold electrode, it is not possible to accurately apply the electrode to the micro-separated small pad (0.5 mm ² ), and in fact, the electrode often protrudes from the top of the micro-pad, resulting in more coverage than necessary. The wire coating may melt and come into contact with the adjacent conductive pattern.

(3) In the general heater electrode welding method, it is difficult to control the amount of heat because the conductive pattern is minute. In addition, general welding machines require stabilization of the welding power source, monitoring of the welding voltage during welding,
Uniform pressure on the electrode tip, stable welding to large substrates, etc., are not taken into account, and therefore, although it can be used for repair purposes, it is not used at all for mass production.

In this way, conventional welding methods
All of these methods are unsuitable for welding minute parts; in particular, the spacing between the conductive patterns is too narrow and they tend to come into contact with adjacent patterns, and furthermore, it is impossible to heat various conductive patterns with different heat capacities with high precision. Also,
Few methods have been considered, and the necessity thereof has not been considered, allowing the base material to be welded on which parts are mounted to be freely exchanged from front to back to facilitate connection.

SUMMARY OF THE INVENTION In order to eliminate these drawbacks, an object of the present invention is to provide a simple and reproducible covered wire welding device for joining covered wires on various conductive patterns having different heat capacities with high precision.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall perspective view of a welding device according to the present invention.

As shown in FIG. 1, the welding device of the present invention includes a welding head 1 that melts and joins a solder layer between a covered wire and a conductive pattern by compression and heating, and a welding head 1 that is placed at a high place using a stand. A power supply section 2, a lighting device section 3 that illuminates the welding work, a connection instruction table 5 that shows the connection points, a magnifying glass 6 that confirms the welding points,
A table section 8 for performing welding work, a substrate holding stand (work pallet) 47 for holding the substrate to be welded, and a control section 9 for controlling the descending time of the head, etc.
It is composed of etc. Furthermore, in FIG. 1, a voltmeter 4 that indicates the power supply voltage, an adjustment dial 11 that adjusts the power supply voltage, a conductive sheet 7 pasted on the table, and earthquake-resistant rubber 10 that fixes the table are shown.
It is shown.

2 is an enlarged perspective view of the welding head 1 shown in FIG. 1, and FIG. 3 is a structural diagram of the welding head 1 as well.

As shown in FIG. 2, the welding head section 1 has a box attached to a supporting support 13 extending laterally from a column 12, and a shank 14, a holder 1,
5 is taken out and a chip 16 is welded to its tip.
is installed. As shown in FIG. 3, a weighted shank 24 having a weighted cone 23 is built inside the box. In this way, the welding head 1 is equipped with a pressure mechanism using the weight shank 24 having the heavy cone 23 and the shank 14 in order to reduce the influence of pressure on the minute conductive pattern.

The weighting shank 24 and the shank 14 connected by the connecting shank 25 act as a pressure rod that transmits the pressure of the heavy cone 23 to the tip 16.

When pressurizing, the shank 14 is pressed down by the weight of the cone 23 via the connecting shank 25, but if it falls by itself, the effect of pressurization on the conductive pattern is large and the pattern may be damaged. Therefore, move air cylinder 19 to shank 1.
4 to adjust the pressurizing speed by controlling the input and exhaust pressures of the cylinder 19, and finer speed adjustments are made using the repulsive force of the spring 20. This control is performed by an air valve control mechanism in the control section 9, and the descending speed and rising speed are controlled. Through this control, the pressure applied to the coating of the covered wire and the rate of pressurization can be controlled to constant conditions. Furthermore, a micro switch 21 and a hand switch 22 are attached to the shaft of the air cylinder 19, so that the switch to start energization is turned on when the electrode chip 16 contacts the substrate and the pressure becomes stable. The micro switch 21 is set.
This allows the timing to start heating the coating to be determined. Furthermore, the hand switch 22
Since this is added, even if the switch 21 is accidentally turned on when polishing the tip of the tip 16 or replacing the tip 16, no electricity will be applied, making the operation very easy.

FIG. 4 is a configuration diagram of the welding power source section 2 in FIG. 1.

As shown in FIG. 4, the welding power source 2 stabilizes the AC input from the power supply terminal 35 with a stable power source 31, controls the welding voltage with a voltage regulator 32, and controls the output of the main circuit welding power source 33. Welding control circuit 3
4, the chip 16 of the holder 15 is heated. Further, the welding voltage is monitored by a voltmeter 36. A more detailed configuration of this welding power source section 2 is described in Japanese Patent Application No. 133697/1983, ``Micro Thermal Welding Apparatus'', which was previously proposed by the present inventor.

As shown in FIG. 1, this welding power source section 2 is set up in a higher place using a stand in order to effectively utilize the table 8, and the center of the power source section 2 has a
A voltmeter 4 for monitoring the welding voltage (absolute value) of the conductive pattern to be welded is attached to perform highly accurate welding. Further, the voltage regulator 32 is located on the front side of the power supply unit 2, and the operator adjusts the voltage using the adjustment dial 11 while checking the monitor voltage during welding. In this way, by changing the welding voltage for each pad of the conductive pattern using the adjustment dial 11, it is possible to apply the amount of heating heat according to the heat capacity of each pad of the welding part.

As shown in FIG. 1, the lighting device section 3 is attached to the front of the stand to brighten the workbench.
Furthermore, since the connection instruction table 5 is also attached to the stand, work efficiency is extremely high. Further, since the satin-like conductive sheet 7 is attached to the table 8, the work pallet 47 can be moved smoothly, and the conductive sheet 7 is grounded.

5 is a perspective view of the substrate holder shown in FIG. 1, and FIG. 6 is a sectional view of the substrate holder shown in FIG. 5 with a substrate held thereon.

As shown in FIG. 6, the board holder 47 has grooves 44 cut in the centers of the frames 41, 43, and 45 so that both the front and back sides can be welded, so that the height of the board 46 remains constant even if it is turned over. , welding on the back side becomes easier.

In addition, as shown in FIG. 5, frames 41, 43, 4
5 is provided with an address scale, and by reading it simultaneously with the sliding scale 42, the X and Y addresses can be read. The sliding scale 42 uses rails to ensure smooth sliding. Furthermore, in frames 41, 43, 45,
It has a mirror finish so that it can move smoothly on the conductive sheet 7.

To weld using the welding device shown in Figure 1, the board to be welded is held on a board holder made of a smooth surface structure frame, and the desired position is confirmed by reading the sliding scale attached to the frame. Then, move the board holder and weld with the welding head while checking the welding location with a magnifying glass. In that case, check the welding voltage with a voltmeter for conductive patterns on the welded substrates with different heat capacities, and adjust the voltage adjustment dial.
Next, the welding head 1 is lowered, and the pressure mechanism automatically applies pressure to the covered wire on the conductive pattern, and the tip 16 is energized, and the heat generated by the tip welds the covered wire and the conductive pattern. .

Since it is equipped with a welding head mechanism as shown in Figures 2 and 3, and a power supply monitoring mechanism as shown in Figure 1, it eliminates unnecessary overheating compared to conventional welding methods. Peeling off conductive patterns,
Problems such as thin wire diameter bending or solder scattering are eliminated. Further, since a substrate holder as shown in FIGS. 5 and 6 is used, arbitrary connection points can be read and wiring can be easily performed even when connection points are mixed on the front and back of the board. Furthermore, as shown in FIG. 1, since the table surface can be widely used, it is possible to connect large substrates, and it is also possible to wire substrates on which components that are sensitive to static electricity are mounted.

As explained above, since the chip 16 can gradually apply a constant pressure to the coated wire on the conductive pattern, not only will the pattern not be damaged by the pressure, but this pressure will also cause the chip 16 to The coating can be melted in a short period of time by heating the coating. In addition, by changing the melting voltage for each pad of the conductive pattern using the adjustment dial 11, it is possible to apply heating heat to each pad according to its heat capacity. There will be no occurrence of poor connections caused by over-melting of the solder, burnout of the conductive pattern, or disconnection of the conductive pattern due to excessive melting of the solder.
Furthermore, the amount of heating heat applied to the coated wire from the chip 16 first melts the coating, and after melting, most of the heating heat is applied to the conductive pattern and the solder, which have good thermal conductivity, and the portion of the coating that has not yet been melted. The amount of heat that goes around is small. As a result, an approximately appropriate amount of heat is applied to the coated portion, and the accident that occurs in the past where the coating components come into contact with adjacent patterns due to excessive melting of the coating and causes shoots between patterns does not occur.

As described above, the welding apparatus of the present invention can apply optimal pressure and heat to the coated wire and various conductive patterns, and therefore can join the two with high precision.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a welding device showing an embodiment of the present invention, FIG. 2 is an enlarged perspective view of the welding head shown in FIG. 1, FIG. 3 is a structural diagram of the welding head, and FIG. FIG. 55 is a perspective view of the board holder shown in FIG. 1, and FIG. 6 is a sectional view of the board fitted to the board holder shown in FIG. 5. . 1... Welding head section, 2... Welding power source section, 3...
...Lighting device section, 4...Voltmeter, 5...Connection instruction table, 6...Magnifier, 7...Conductive sheet, 8...Table, 9...Control unit, 10...Earthquake-resistant rubber, 11...
... Voltage adjustment dial, 12 ... Support, 13 ... Support support, 14 ... Shank, 15 ... Holder, 16 ... Chip, 17 ... Switch, 18 ...
...Air hose, 19...Air cylinder, 20
...Spring, 21...Micros Itsuchi,
22... Hand switch, 23... Weight, 24...
Weighted shank, 25... Concatenated shank, 31...
Stable power supply device, 32... Voltage regulator, 33... Main circuit welding power source, 34... Welding control circuit, 35...
Power terminal, 36...Voltmeter, 41...Scale frame, 42...Sliding scale, 13...Support, 44...Groove, 45...Side frame, 46...
Substrate, 47...Substrate holding stand (work pallet).

Claims (1)

[Claims] 1. In a device that melts a solder layer formed on a conductive pattern and joins a covered wire onto the conductive pattern, a pressurizing rod supporting a heat-generating metal electrode chip and applying pressure via the pressurizing rod are used. A welding head having a weight for applying pressure and a speed adjusting means connected to the pressure rod for slowing down the pressurizing speed, and an electrode tip of the welding head while adjusting the welding voltage for conductive patterns having different heat capacities. A covered wire welding device having a power supply control means for generating heat.