JPH1051126A - Automatic soldering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an automatic soldering apparatus by which a soldering defect can be reduced by a method wherein a means which adjusts the height of a board is installed and a means which adjusts the jet speed of molten solder stepwise is installed. SOLUTION: In a rail raising and lowering part, the height of a board conveyance rail 10 used to convey a printed-circuit board 9 is adjusted between a conveyance height H1 and a solder height H2. On the other hand, by using an inverter which supplies a driving current to a motor 17 which drives the shaft of a pump 15 used to send out molten solder, the jet speed of the moletn solder is controlled so as to be adjusted stepwise in correspondence to a plurality of treatment processes. Thereby, the jet speed of the molten solder can be adjusted stepwise so as to correspond respectively to a process in which surface oxide dregs are removed from the molten solder being jetted, a process in which a soldering operation is executed to the printed-circuit board 9 and a process in which solder stuck between component terminals at the printed- circuit board 9 is cut. As a result, the soldering operation can be executed in a state that surface solder is removed from molten solder on a jet port 11, and the solder at the printed-circuit board can be cut accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic soldering apparatus, and more particularly to an automatic soldering apparatus having a function of switching the speed of a solder jet and the height of a substrate stepwise.

[0002]

2. Description of the Related Art Conventionally, a soldering apparatus performs a soldering process by lowering a printed circuit board on a molten solder surface where a constant jet is maintained, and inclining a transfer rail after soldering to print the printed circuit board from the solder jet surface. Was cut off the solder by separating the lower surface.

[0003]

However, in the conventional soldering apparatus, the solder is cut off from the lower surface of the printed circuit board by inclining the transfer rail, so that the solder adhering between the terminals of the electronic component is removed. There is a problem that the soldering failure due to a bridge, a short circuit or the like occurs and the failure rate increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an automatic soldering apparatus that can contribute to a reduction in defective soldering.

[0005]

According to the first aspect of the present invention,
To solve the above problems, an automatic soldering apparatus for automatically soldering molten solder to a substrate, a substrate height adjusting means for adjusting the height of the substrate corresponding to a plurality of processing steps, The gist of the present invention is to have a jet speed adjusting means for adjusting the jet speed of the molten solder in a stepwise manner corresponding to a plurality of processing steps. Further, the jet velocity adjusting means includes a surface oxide residue removing step of removing surface oxide residue from at least the molten solder surface in the jet, a soldering step of soldering the substrate, and cutting the solder attached between the component terminals of the substrate. It is preferable to adjust the jet velocity of the molten solder stepwise in accordance with each of the attached solder cutting steps. Further, the substrate height adjusting means includes a surface oxide residue removing step of removing surface oxide residue from at least the molten solder surface in the jet, a soldering step of soldering the substrate, and cutting the solder attached between the component terminals of the substrate. It is preferable to adjust the height of the substrate between the transport height and the soldering height in accordance with each of the attached solder cutting steps. Furthermore, it is preferable that the jet velocity adjusting means includes a pump for feeding molten solder, a motor for driving a rotary shaft of the pump, and an inverter for supplying a driving current to the motor.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a mechanical system of an automatic soldering apparatus according to an embodiment of the present invention. FIG.
As shown in FIG. 1, the mechanical system of the automatic soldering apparatus 1 includes a solder layer 5 for storing the molten solder 3, a solder tube 13 for jetting the jet solder 7 from a jet port 11 onto a printed circuit board 9 on which electronic components 8 are arranged. A pump 15 for feeding the molten solder 3 toward the jet port 11 and a motor 17 for driving a rotating shaft of the pump 15 at an arbitrary speed. In addition, the automatic soldering apparatus 1 can also be applied to a point soldering apparatus for soldering only the electronic components 8 arranged in an arbitrary area of the printed circuit board 9.

Next, FIG. 2 is a diagram showing a configuration of a control system of the automatic soldering apparatus according to the embodiment of the present invention. As shown in FIG. 2, the control system of the automatic soldering apparatus 1 includes a control unit 21 for controlling the apparatus 1 based on a control program and control data, and an interrupt after a processing time set corresponding to each processing step. A timer 23 that generates a signal, an inverter 25 that generates a three-phase AC current in response to a torque command from the control unit 21, and a drive torque that is freely generated according to the magnitude of the three-phase AC current from the inverter 25. A motor 17;
The board transfer section 27 for transferring the printed circuit boards 9 on the board transfer rail 10 sequentially, and the height of the board transfer rail 10 for transferring the printed board 9 is set between the transfer height H1 and the soldering height H2. And a rail elevating unit 29 to be adjusted.

The control section 21 has a table in the internal ROM in which the correspondence between the jet velocity and the torque command is stored in advance. The control unit 21 can set the torque command by manual operation.

Next, with reference to FIGS. 4 and 5, the operation in each processing step of the automatic soldering apparatus will be described using the flowchart shown in FIG. The operation of each unit shown in this flowchart is controlled by the control unit 21.

First, in step S10, as shown in FIG. 4 (a), as a surface oxide residue removing step for removing surface oxide residue from the surface of the molten solder in the jet, the rail elevating unit 29 moves the substrate transport rail 10 to the upper limit. Set to position H1. Next, the board transport unit 27 moves the printed board 9 to a soldering point.

Next, as shown in FIG. 5 (a), in order to remove the oxidized cake by injecting the wave height of the jet solder 7 from the jet port 11 at a high speed V1, the control unit 21 controls the high torque. A torque command is generated and given to the inverter 25, and the motor 1
7 is rotated. The wave height from the jet 11 can be adjusted by adjusting the torque command output from the control unit 21.

Next, in step S20, as a soldering preparation step, as shown in FIG.
Starts the lowering of the substrate transport rail 10 from the upper limit position H1 to the lowering position H2. Next, FIG.
As shown in the figure, in order to change the wave height of the jet solder 7 jetted from the jet port 11 from the high speed V1 to the medium speed V2 to perform the soldering, the control unit 21 generates a medium torque torque command to 25 to rotate the motor 17.

Next, in step S30, a processing time of 3.5 to 4 seconds is set in the timer 23 as a soldering step. Next, as shown in FIG. 4C, the rail elevating unit 29 moves the substrate transport rail 10 to the lowermost position H, which is the lower limit position.
Set to 2. Next, as shown in FIG. 5 (c), in order to fix the wave height of the jet solder 7 jetted from the jet port 11 to the medium speed V2 and to perform soldering, the control unit 21 issues a medium torque torque command. To the inverter 25 to rotate the motor 17. Further, the soldering is continued until an interrupt signal is generated 3.5 to 4 seconds later by the timer 23.

Next, in step S40, a processing time of 3.5 seconds to 4 seconds is set in the timer 23 as an adhesion solder cutting step.

Next, as shown in FIG. 4 (d), the rail elevating unit 29 continuously sets the substrate transport rail 10 to the lowering position H2 which is the lower limit position. Next, the soldering is continued by the timer 23 until an interrupt signal is generated 3.5 to 4 seconds later. Here, as shown in FIG. 5D, in order to change the wave height of the jet solder 7 jetted from the jet port 11 from the medium speed V2 to the low speed V3 so as to perform the solder cutting, the control unit 21 has a low torque. New torque command for inverter 2
5 to rotate the motor 17. As a result, the terminal portion of the electronic component 8 is soldered so as to lower the jet flow to the terminal lead of the electronic component 8 on the printed circuit board 9.

Next, in step S50, as a termination step, after the soldering of the terminal portion of the electronic component 8 is terminated, as shown in FIG. From the descending position H2 to the upper limit position H
Start climbing towards 1. Next, the board transfer rail 1
After 0 has risen to the upper limit position H1, as shown in FIG. 5 (e), in order to change the wave height of the jet solder 7 to be jetted from the jet port 11 from the low-speed V3 to the high-speed V1, and to remove oxide cake, The control unit 21 generates a high torque command and supplies it to the inverter 25 to rotate the motor 17. Next, the board transport unit 27 transports the printed board 9 after soldering to the right and discharges the printed board 9, and moves a new printed board 9 to a soldering position.

As described above, the height of the printed circuit board 9 is adjusted by the rail elevating unit 29 corresponding to a plurality of processing steps, while the pump 15 for feeding molten solder and the motor 17 for driving the rotary shaft of the pump 15 are provided. And an inverter 25 that supplies a drive current to the motor 17 controls the molten solder jet speed in a stepwise manner corresponding to a plurality of processing steps. Surface oxide residue removing step (a) for removing residue, soldering step (c) for soldering to printed circuit board 9, printed circuit board 9
The jet velocity of the molten solder can be adjusted stepwise in accordance with the attached solder cutting step (d) for cutting the solder attached between the component terminals. As a result, the soldering can be performed in a state where the surface oxide residue is removed from the molten solder surface on the jet port 11, and the soldering of the printed circuit board 9 that has been subjected to the soldering can be accurately performed.

The rail elevating section 29 includes a surface oxide residue removing step (a) for removing surface oxide residue from at least the molten solder surface in the jet, a soldering step (c) of soldering to the printed circuit board 9, and a printing step. The height of the printed circuit board 9 is set to the transfer height H1 and the soldering height H corresponding to the attached solder cutting step (d) for cutting the solder attached between the component terminals of the board 9 respectively.
2 can be adjusted. As a result, spout 1
When removing surface oxide residue from the molten solder surface on 1,
The printed circuit board 9 can be separated from the surface of the molten solder to prevent the jet solder 7 from sticking, and the soldered printed circuit board 9 can be accurately cut off.

Therefore, it is possible to remove the surface oxide residue adhering to the solder surface on the printed circuit board as in the prior art,
There is no residue of the solder adhering between the terminals of the electronic component, the occurrence of soldering failure due to a bridge, a short circuit or the like can be reduced, and the soldering quality can be improved. Specifically, the soldering failure rate of 25%, which has conventionally occurred, could be reduced to about 1.5%.

[0020]

As described above, according to the first aspect of the present invention, soldering can be performed in a state in which surface oxide residue is removed from the surface of the molten solder in the jet. Soldering after the mounting can be performed accurately. In addition, when removing the surface oxide residue, the printed circuit board can be separated from the molten solder surface, and the solder can be accurately cut after the soldering. Therefore,
It removes surface oxide residue adhering to the solder surface on the printed circuit board as before, leaving no residue of the solder adhering between the terminals of the electronic components, resulting in poor soldering due to bridges, shorts, etc. Generation can be reduced, and soldering quality can be improved. Specifically, the soldering failure rate of 25%, which has conventionally occurred, could be reduced to about 1.5%.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a mechanical system of an automatic soldering apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a control system of the automatic soldering apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart for explaining a soldering operation of the automatic soldering apparatus.

FIG. 4 is a timing chart showing a substrate conveyance and a jet flow.

FIG. 5 is a diagram showing each step of a soldering process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Automatic soldering apparatus, 3 ... Molten solder, 5 ... Solder layer, 7 ... Spout solder, 8 ... Electronic components, 9 ... Printed circuit board, 10 ... Board transfer rail, 11 ... Spout port , 13
…… Solder cylinder, 15… Pump, 17 …… Motor, 21…
... Control unit, 23 ... Timer, 25 ... Inverter, 27
... Board transfer section, 29 rail elevating section.

Claims (4)

[Claims] 1. An automatic soldering apparatus for automatically soldering molten solder to a substrate, comprising: a substrate height adjusting means for adjusting a height of the substrate corresponding to a plurality of processing steps; An automatic soldering apparatus comprising: a jet speed adjusting means for adjusting a jet speed of molten solder in a stepwise manner in accordance with a processing step. 2. The method of claim 1, wherein the jet velocity adjusting means comprises: a surface oxide debris removing step of removing surface oxide debris from at least a molten solder surface in the jet; a soldering step of soldering the substrate; 2. The automatic soldering apparatus according to claim 1, wherein the jet velocity of the molten solder is adjusted stepwise in accordance with each of the attached solder cutting steps for cutting the solder. 3. The substrate height adjusting means includes: a surface oxide residue removing step of removing surface oxide residue from at least a molten solder surface in a jet; a soldering step of soldering a substrate; 2. The automatic soldering apparatus according to claim 1, wherein the height of the substrate is adjusted between the transport height and the soldering height in correspondence with the attached solder cutting step for cutting the solder. 4. The jet flow adjusting means according to claim 1, wherein said jet velocity adjusting means includes a pump for feeding molten solder, a motor for driving a rotating shaft of the pump, and an inverter for supplying a driving current to the motor. Automatic soldering equipment.