WO1989008527A1

WO1989008527A1 - Method and apparatus for removing defective solder

Info

Publication number: WO1989008527A1
Application number: PCT/JP1989/000190
Authority: WO
Inventors: Seiji Kawaguchi
Original assignee: Apollo Seiko Ltd.
Priority date: 1988-03-17
Filing date: 1989-02-23
Publication date: 1989-09-21
Also published as: JPH0258027B2; JPH01237073A

Abstract

The method and apparatus for removing defective solder according to the present invention are characterized by pressing a suction wire onto the defective solder on a printed board, heat melting the defective solder while supplying a small quantity of molten solder to the suction wire, and removing the melted defective solder by sucking utilizing a capillary action of the suction wire. Therefore, even when a soldering operation fails with defective solder remaining on a printed board, the defective solder can be removed simply without fail. This enables the re-soldering to be done easily and the overall efficiency of a soldering operation to be improved. When the apparatus is provided with the soldering function in addition to the defective solder removing function, a correct soldering operation can be carried out immediately after the defective solder has been removed. Since the defective solder is removed by utilizing the capillarity of the suction wire, i.e., a physical phenomenon, troubles rarely occur involving the defective solder removing operation, and the maintenance work for the apparatus can be advantageously carried out.

Description

Description Method and equipment for removing defective solder

Technology field>

The present invention relates to a method and an apparatus for removing defective solder. For example, the present invention relates to a method and an apparatus for removing defective solder that can easily and reliably remove defective solder when soldering on a printed circuit board for mounting various electronic components and the like fails. 0

Background technology>

Pins for electronic components (for example, ICs and resistors) are mounted on the printed circuit board by soldering. And this soldering work is performed by manual work by workers or mechanical work by automatic soldering equipment, but inevitably there are defective parts of solder.

In order to remove such defective solder, conventionally, the defective solder was melted, and the molten defective solder was removed by suction using a vacuum.

However, in such a conventional vacuum-type removal method, since the molten defective solder is easily solidified, the solder is quickly solidified and clogged in the vacuum mechanism, resulting in a decrease in work reliability and maintenance. There was a problem in terms.

<Disclosure of the Invention>--The present invention has been made by paying attention to such a conventional technique, and a method and a device for removing defective solder which can surely remove defective solder. The company will not provide a device.

In order to achieve the above object, a method and an apparatus for removing defective solder according to the present invention are to reliably remove molten defective solder by utilizing a capillary phenomenon of a suction wire.

Specifically, the suction wire is pressed against the defective solder on the print substrate, and while applying a small amount of molten solder to the suction wire, the defective solder is heated and melted, and the melted defective solder is sucked. It is designed to absorb and remove by utilizing the capillary action of the wire (first invention).

After the suction wire is pressed against the defective solder, if a small amount of molten solder is applied to the suction wire and a heat treatment is performed on the defective solder by using a soldering iron or a laser beam, the defective solder is melted and melted. At the same time, it is sucked into the sucking wire by capillary action. The melted defective solder has a large surface tension, and is reliably and completely sucked into the sucking wire. In addition, since a small amount of molten solder is applied to the suction wire, the small amount of molten solder becomes "water", and the heat transfer efficiency of the suction wire increases, and the heating is directly transmitted to the defective solder. The solder is easily melted, and the melted defective solder is easily absorbed by the suction wire.

As a manual device for removing the defective solder, a suction wire supply unit that can supply a suction wire to the tip of the iron tip is provided integrally with a soldering iron body having a tip at the tip. A solder wire removing unit capable of supplying a suction wire to a tip of a soldering iron tip to a soldering iron body having a soldering iron tip at the tip thereof; Ko A device for removing defective solder, characterized in that the device is provided with a thread solder supply unit capable of supplying thread solder to the tip of the tip (3rd invention);

A suction wire supply unit having a suction wire cutter mechanism for freely supplying a suction wire to the tip of the soldering tip and cutting the supplied suction wire to a soldering iron body having a soldering tip at the tip; The present invention provides a thread solder supply unit capable of freely supplying thread solder to the tip of the present invention, and a defective solder removing device (fourth invention) characterized in that the thread solder supply unit is provided physically.

Further, as an automatic device for removing the above-mentioned defective solder, a pin is fixed on a print substrate while gripping a suction wire on a head of a robot arm which is freely movable and rotatable at any position. A fifth embodiment of the present invention provides a combination of a set finger unit for pressing against defective solder and a solder cottage for applying heat treatment to the defective solder.

Brief description of the drawing>

FIG. I is a schematic explanatory view of a manual defective solder removing device showing one embodiment of the present invention,

FIG. 2 is an explanatory view showing a force-pumping mechanism for a suction wire, and FIGS. 3 (a), (b) and (c) are enlarged cross-sectional views of a printed circuit board showing a step of removing defective solder in a manual defective solder removing apparatus, respectively.

FIG. 4 is a plan view of an automatic defective solder removing apparatus showing another embodiment of the present invention,

Figure 5 is a side view of an automatic defective solder removing ^device: FIG. 6 is a schematic explanatory view showing a wire feeder blotting, and FIG. 7 (a) (b) (c ) is, in each automatic bad solder removing device Bad half FIG. 4 is an enlarged cross-sectional view of a printed circuit board showing a step of removing a field and a soldering process.

BEST MODE FOR CARRYING OUT THE INVENTION>

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1 to 3 (a), (b) and (c) are views showing a manual defective solder removing apparatus according to an embodiment of the present invention. The manual defective solder removing device 1 mainly includes a bistor-shaped solder iron body 2, a suction wire supply unit 4 capable of freely supplying a suction wire 3, and a thread solder supply unit 7.

The soldering iron body 2 has a heater part 5 at the upper part, and a bent iron tip 6 is provided at the tip of the heater part 5. Further, a guide cylinder 8 extending toward the tip of the iron tip 6 is attached to the tip of the thread solder supply unit 7 fixing the heater 5. A winding roll 10 around which the flux-containing thread solder 9 is wound is disposed at the rear of the heater section 5. The thread solder 9 passes through the inside of the thread solder supply unit 7 to form a pair of delivery rollers 11. The guide tube 8 can be supplied from the front end while being held between the guide tubes.

On the other hand, a suction wire supply unit 4 is provided at the lower end of the thread solder supply unit 7. A winding roll 12 around which a strip-shaped suction wire 3 made of a thin steel wire is wound is disposed below the suction wire supply unit 4, and the suction wire 3 is sucked by the wire supply unit. In the same manner as the thread solder 9, it can be supplied to the tip of the iron tip 6 from the gun barrel 14, which is formed to project from the tip, while being sandwiched between the pair of sending rollers 13 through the inside of the I'm sorry. Figure 7 shows the thread solder supply unit 7. Although it is difficult to see on the surface, two switch buttons 15 are arranged in parallel, and by pressing these switch buttons 15, a certain amount of the thread solder 9 and the suction wire 3 can be supplied. The iron tip 6 of the heater section 5 is heated when the power cord 16 at the end of the thread solder supply unit 7 is connected to the power supply. '

Further, the suction wire supply unit 4 is provided with a suction wire force cutter mechanism 50. That is, a bar-shaped piston is attached to the nail cutter-shaped force cutter body 52 fixed with the cutting edge 51 facing the tip of the guide cylinder 14 and the stepped portion 53 of the cutter body 52. A cylinder 55 is provided for closing the cutting edge 51 by pressing the button 54.

Next, a method of using the manual defective solder removing device 1 will be described (see FIGS. 3 (a), (b) and (c)).

Reference numeral 17 denotes a printed circuit board to which pins 19 of an IC 18 as an electronic component are soldered in a state of protruding to the other side. The solder fixing this pin 19 is not shown in the drawing, but is defective solder 20 which has caused a bridge with the adjacent pin (a phenomenon in which the solder and the solder are connected). Then, the suction wire 3 supplied from the thread solder supply unit 7 is placed on the defective solder 20. Then, the iron tip 6 of the manual defective solder removing device 1 is pressed against the suction wire 3 and simultaneously, the thread solder 9 is sent out to the iron tip 6 [see FIG. 3 (a)]. By doing so, the solder wire 9 is slightly melted at the iron tip 6 and absorbed by the suction wire 3. Since the heat from the iron tip 6 is transmitted to the defective solder 20 via the suction wire 3, the defective solder 20 is immediately melted. Defective solder 20 melted is absorbed by capillary action Is absorbed by the wire 3 [see FIG. 3 (b)]. Nothing remains after the defective solder 20 is absorbed by the suction wire 3. Then, the switch of the suction wire cutter mechanism 50 (not shown) is pushed, the barbed piston 54 is protruded, the cutting edge 51 is closed, and the tip of the suction wire 3 that has absorbed the bad solder 20 The portion is cut (see FIG. 3 (c)), and the next removal operation can be performed at the tip of the new suction pipe 3.

In addition, the manual defective solder removing device 1 according to the present embodiment can not only remove the defective solder 20 as described above, but also perform accurate soldering again after the defective solder 20 is removed. One of the special features. That is, the pin 19 can be soldered by pressing the iron tip 6 against the pin 19 and supplying only the thread solder 9. Therefore, when the defective solder 20 is generated, the defective solder 20 can be removed and re-soldering can be performed by the manual defective solder removing device 1.

4 to 7 (a), (b) and (c) are views showing an automatic defective solder removing apparatus according to another embodiment of the present invention. The same parts as those in the previous embodiment are denoted by the same reference numerals, and duplicate description will be omitted.

The automatic defective solder removing device 21 according to this embodiment is mounted on a printed circuit board 17 with a suction wire 23 attached to a head 22 of a robot arm that is freely movable and rotatable. It is a combination of a set finger unit 24 facing the bad solder 20 fixing the pin 19 and a solder cot unit 25 heating the bad solder 20. The set finger unit 24 and the solder connector 25 both vertically move the finger unit 28 and the iron unit 29 independently by the cylinder 26.27. It is possible, and it is inclined in a V-shape around a point (pin 19) on the printed board 17. Reference numeral 30 denotes a suction wire supply device for sequentially supplying suction wires 23 of a fixed length. The suction wire supply device 30 is disposed beside the stage 31 to which the printed circuit board 17 is fixed.

Further, the automatic defective solder removing device 21 is electrically connected to an automatic solder inspection device (not shown), and a signal from the automatic solder inspection device determines the defective solder 20 determined to be “defective”. It can be automatically positioned and moved to the position.

A pair of left and right claws 3 that can freely open and close the toes 33 at the center of the shaft 32 is provided on the finger part 28 that can move up and down of the set finger unit 24. In other words, when the tip of the twisted biston 35 is inserted between the upper ends of the claws 34, the toes 33 are opened, and when removed, the toes 33 are closed by a constant urging force of a constant spring (not shown). It has become. Therefore, the suction wire 23 having a certain length can be held between the toes 33.

An iron tip 36 is provided at the tip of the iron part 29 of the solder iron kit 25, and a guide tube 3 which can supply a flux-containing thread solder 9 to the tip of the iron tip 36 is provided. 7 are provided. The guide cylinder 37 is connected to a not-shown thread solder supply device to supply a certain amount of thread solder 9.

The suction wire supply device 30 includes a take-up roll 38 around which the suction wire 23 is wound, a delivery roller 39 for sending a predetermined amount of the suction wire 23, and a pair of upper and lower force meters 40. '(See Fig. 6). Then, the suction wire 23 wound around the winding roll 38 is sent out, and is protruded from the outlet by a certain amount by the roller 39. When the set finger unit 24 moved by the head 22 of the robot arm comes to grasp the suction wire 23, it is cut by the cutter 40, and the suction wire 23 of a fixed length is formed. Can be transferred to the set finger unit 24.

Next, a method of using the automatic defective solder removing device 21 will be described (see FIGS. 7 (a), (b) and (c)).

First, by moving the head 22 of the mouth-bottom arm, the set fin garnet 24 and the solder cot nit 25 are moved above the suction wire feeder 30 and the toe of the set fin garnet 24 is moved. At 3 3, insert a suction wire 2 3 of a fixed length size. Then, according to a signal from an automatic inspection device (not shown), the set finger fin 24 and the solder cot nit 25 are moved above the printed circuit board 17, and the defective solder 20, which is a work target, is transferred to the work board 20. To the top of the pin 19, which has been fixed. Then, the iron part 29 and the finger part 28 are lowered by the cylinders 26 and 27, respectively, along the inclination direction. Then, the suction wire 23 is put on the defective solder 20, and the iron tip 36 is pressed on the suction wire 23, and at the same time, a small amount of thread solder 9 is sent to the iron tip 36. See Fig. 7 (a)]. By doing so, the solder wire 9 is slightly melted at the iron tip 36 and absorbed by the suction wire 23. Since the heat from the iron tip 36 is transmitted to the defective solder 20 via the suction wire 23, the defective solder 20 is immediately melted. The molten defective solder 20 is absorbed by the suction wire 23 by capillary action: [see FIG. 1 (b)].

Then, the defective solder 20 absorbed by the suction wire 23 is absorbed. Then, after moving the set finger unit 24 and the solder cottage 25 upward at once, this time, only the solder cottage 25 is lowered again to remove the defective solder 20. By pressing the iron tip 36 against the pin 19 and supplying only the thread solder 9, the soldering of the pin 19 can be "re-executed" (see Fig. 7 (c)). Then, when the “redo” of the soldering is completed, the movement of the head 22 of the robot arm causes the solder couplant 25 and the set finger garnet 24 to be largely moved, respectively, to remove the defective solder 20. Discard absorbed suction wire 23 in place. Then, the above operation is repeated for another defective solder in accordance with the next signal from the automatic solder inspection apparatus, and “redo” of all the defective solders 20 on the printed circuit board 17 is sequentially performed. be able to.

In the above description, as an example of the “heating process”, only heating using a soldering iron is used, but irradiation heating using a YAG laser beam or the like may be used. Furthermore, a strip-shaped braided thin steel wire is taken as an example of the “suction wire”, but the invention is not limited to this. In addition, with respect to the automatic defective solder removing device 21, the supply of the suction wire may be performed by the separate-type suction wire supply device 30 as in the above-described embodiment, but the set finger unit 24 itself is used. You may make it attach a suction wire supply mechanism.

The method and apparatus for removing defective solder according to the present invention have the contents as described above. Therefore, even if defective solder fails to be soldered, the defective solder can be easily and reliably removed. The soldering can be easily re-executed and the overall workability of the soldering work can be improved. • i> o

In addition, as shown in the embodiment, not only the function of removing defective solder but also the function of soldering can be provided, so that it is highly versatile in soldering work and should be combined with an automatic solder inspection device etc. This makes it possible to automatically “redo” defective solder.

Furthermore, since the defective solder is removed by utilizing the physical phenomenon called the capillary phenomenon of the suction wire, there are few troubles in the removing operation, which is advantageous in maintenance.

Claims

The scope of the claims

(1) A suction wire is pressed against defective solder on a printed circuit board, and while applying a small amount of molten solder to the suction wire, the defective solder is heated and melted. A method of removing defective solder, characterized in that the solder is removed by utilizing capillary action.

(2) A soldering iron body having a soldering iron tip at the tip is provided with a sucking wire supply unit capable of supplying a sucking wire to the tip of the iron tip, and is provided with a soldering iron. Removal device.

(3) A suction wire supply unit that can supply a suction wire to the tip of the iron tip, and a thread solder supply that can supply the solder wire to the tip of the iron tip. Unit and the body are provided physically, so that defective solder is removed.

(4) A suction wire supply unit having a suction wire cutter mechanism capable of supplying a suction wire to a soldering iron body having a soldering iron tip at a tip thereof and capable of cutting off the supplied suction wire. And a thread solder supply unit capable of supplying thread solder to a tip of a soldering iron tip, and a defective solder removing device characterized by being provided physically.

(5) A set finger unit which pushes a suction wire to the bad solder on the printed circuit board and puts it on the head of the robot arm, which can be freely moved and rotated, and heats the bad solder. An apparatus for removing defective solder, which is assembled with a solder cottage for applying soldering.