JP2021193702A - Laser soldering method - Google Patents

Abstract

To provide a laser soldering method capable of achieving high reliability of soldering by suppressing an increase in the time for setting soldering conditions corresponding to a soldering part.SOLUTION: In a laser soldering method, irradiating a soldering part of a substrate 2 to be soldered with a laser beam from a laser head 10 for soldering, a movement process and a setting process are concurrently performed by setting soldering conditions from the movement process of the laser head 10, and completion of the relative movement to a soldering position is included as a start condition of soldering.SELECTED DRAWING: Figure 3

Description

The present invention relates to a laser soldering method.

Conventionally, when mounting an electronic component on a substrate, a laser soldering method has been adopted in which a laser beam is irradiated from a laser head to the soldered portion of the substrate to solder the soldered portion (see, for example, Patent Document 1). ).
Specifically, for example, as a soldering portion for soldering a land around a through hole in a substrate and a terminal of an electronic component, the solder is melted by the heat of a laser beam to perform soldering. With this laser soldering method, it is possible to perform non-contact soldering even in extremely small places that cannot be handled by the method using a soldering iron, and the load on the board can be reduced while suppressing the generation of solder balls. There are advantages such as being able to plan.

Japanese Unexamined Patent Publication No. 2011-29655

In the conventional laser soldering method, problems such as burning of the substrate by the laser beam and soldering failure due to heat drawing or the like may occur. Therefore, it is conceivable to set or switch the soldering conditions such as the laser output for each soldered portion according to the land diameter and the like on the substrate.
However, in the actual manufacturing process, for example, soldering is performed over a dozen places on one board, and if the soldering conditions corresponding to each place are set for a large number of boards, the conditions are switched. It will take a lot of time just for that.

The present invention has been made in view of the above circumstances, and an object thereof is to suppress an increase in time due to setting of soldering conditions corresponding to a soldered portion, and to improve soldering reliability. The purpose is to provide a laser soldering method that can be used.

According to the invention described in claim 1, it is possible to set the soldering conditions corresponding to the individual soldering portions in the setting process, and the setting of the soldering conditions and the relative movement of the laser head (10) can be performed. It can be performed in parallel, and the time can be shortened as compared with the case where the soldering conditions are set after the relative movement of the laser head.
In addition, since the start condition includes the completion of the relative movement of the laser head to the soldering position, soldering is performed at an appropriate timing without causing a problem such as irradiating the laser beam during the relative movement of the laser head. Soldering can be started and a reliable connection can be made as a whole.

Schematic diagram showing a schematic configuration of the entire apparatus for explaining a laser soldering method in one embodiment. The figure which shows the flow of processing by the cooperation of the main control device, the supply control device and the laser control device in this equipment. Time chart showing the setting of soldering conditions and the timing of relative movement of the laser head Time chart to explain the operation timing when starting soldering in the conventional configuration

Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. The laser soldering apparatus 1 schematically shown in FIG. 1 includes a laser head 10 that irradiates a laser beam for soldering, and a base 11 on which a substrate 2 to be soldered is set.
The substrate 2 is a rectangular plate-shaped circuit board on which an electronic component 3 is mounted, and has a plurality of through holes 4 penetrating in the plate thickness direction and lands 5 provided around each of the through holes 4. The terminal 3a and the land 5 of the electronic component 3 inserted into the through hole 4 of the substrate 2 are soldered portions that are electrically connected via solder.

Although not shown, it is assumed that one substrate 2 has, for example, 12 soldered portions, and FIG. 1 shows, for convenience, one soldered portion as a representative. In the following, the tip side of the terminal 3a of the electronic component 3 in the soldered portion in the figure is upward, and the opposite side is downward. Further, the plate thickness direction of the substrate 2, which is the vertical direction in FIG. 1, is defined as the Z direction. Further, the left-right direction of the figure along one side of the peripheral portion of the substrate 2 is the X direction, and the direction orthogonal to the paper surface of the figure is the Y direction.

In the laser soldering apparatus 1, the laser head 10 can move relative to the substrate 2 in the X direction, the Y direction, and the Z direction by using, for example, a robot arm (not shown) as a moving means. In this case, the laser head 10 is provided at the tip of the articulated robot arm, and by driving each arm, the irradiation region of the laser beam is relatively moved so as to match the terminal 3a and the land 5 to be soldered. (Refer to the optical axis O of the laser beam). In the moving step of the laser head 10, the setting surface 11a of the base 11 which is the setting portion of the substrate 2 may be moved together with the substrate 2 as a so-called XY table. Hereinafter, the “relative movement” of the laser head 10 is also simply referred to as “movement”.

The thread-shaped solder represented by reference numeral 12 in FIG. 1 is a thread solder 12 whose supply source is the solder supply device 13. The solder supply device 13 includes a solder guide 13a provided on the tip end side of the robot arm. As a result, the solder supply device 13 is configured to feed the solder thread 12 from a predetermined direction toward the soldered portion while guiding the solder thread 12 with the solder guide 13a. Although the solder guide 13a and the laser head 10 are shown at positions separated from each other in FIG. 1 for convenience of explanation, the solder guide 13a is assumed to be moved together with the laser head 10 by the robot arm.

The laser soldering apparatus 1 is provided with, for example, a carry-in belt, a carry-out belt, etc. for carrying in / out the substrate 2 as peripheral equipment, and the entire equipment including the peripheral equipment thereof is the equipment 15 or the main piece. It is called equipment 15. In this equipment 15, in addition to the carry-in step of carrying the substrate 2 to the set surface 11a via the carry-in belt and the carry-out step of carrying out the substrate 2 to the outside of the equipment via the carry-out belt, the moving step of the laser head 10 A series of steps including a setting step for setting soldering conditions, which will be described later, are automatically performed (see FIG. 2 to be described later).

Here, the main control device 16 that controls the entire equipment 15 shown in FIG. 1 is mainly composed of a microcomputer and has a storage unit including a ROM, a RAM, and the like. Various actuators in the robot arm and the like and an operation input unit (not shown) are connected to the main control device 16, and a laser control device 17, a supply control device 18, and the like are connected to the main control device 16. The storage unit of the main control device 16 stores the control program, coordinate data corresponding to each soldered portion on the substrate 2, soldering conditions associated with the soldered portion, and the like. Then, the main control device 16 communicates with the laser control device 17 and the supply control device 18, and executes the processing related to the series of steps in cooperation with the control devices 17 and 18.

The coordinate data specifies, for example, the laser irradiation position to which the laser head 10 is moved in the moving step by the X coordinate, the Y coordinate, and the Z coordinate, and the offset from the standby position of the laser head 10 to the laser irradiation position. It is defined as the coordinates or the offset coordinates corresponding to the positions of the individual soldered portions from the reference position on the substrate 2. Specifically, the coordinate data is stored for each type of the substrate 2, and for example, when there are 12 soldered portions on one substrate 2, the first soldered portion, the second soldered portion, and the like. ... It is assumed that it is stored together with the order data for sequentially moving the laser head 10 corresponding to each position of the 12th soldering portion. As a result, the main control device 16 controls various actuators based on the coordinate data in the moving process, and sequentially moves the laser head 10 to the soldering position, that is, the laser irradiation position.

The laser control device 17 controls an oscillation unit (not shown) that generates laser light, and is mainly composed of a microcomputer having a storage unit. The laser beam output from the oscillating unit is emitted from the laser head 10 toward the substrate 2 along the optical axis O. Prior to the irradiation of the laser beam, the laser control device 17 communicates with the main control device 16 regarding the soldering conditions, and sets the control parameters related to the irradiation of the laser beam.
The control parameters related to the irradiation of the laser beam include, for example, the laser output (W) of the laser beam and the irradiation time (Sec). Further, the control parameter is stored in association with the offset coordinates for each soldered portion or the order data according to the type of the substrate 2.

The supply control device 18 controls the solder guide 13a and the solder supply device 13, and is mainly composed of a microcomputer having a storage unit. Prior to the irradiation of the laser beam, the supply control device 18 communicates with the main control device 16 regarding the soldering conditions and sets control parameters related to the supply of the solder material.
The control parameters related to the supply of the solder material are, for example, the solder supply angle θ between the solder thread 12 and the surface of the substrate 2 (upper surface in FIG. 1), the solder supply direction around the land 5 seen from the upper surface side, and the solder thread 12. Including feed rate. Further, the control parameters are stored in association with offset coordinates or order data for each soldered portion according to the type of the substrate 2.

As the soldering condition, for example, a condition such as setting the size of the irradiation region or the diameter of the laser beam so that the laser beam does not protrude from the land 5 may be added. Further, the main control device 16, the laser control device 17, and the supply control device 18 each have an operation input unit such as a touch panel (not shown), and can input settings related to each teaching or soldering condition in advance.

By the way, the soldering conditions are set according to the shape and dimensions of the land 5 for each type of the substrate 2 in consideration of the heat drawing and the like described in "Problems to be solved". Quality and reliability can be improved.

However, if the soldering conditions include various parameters and the setting / switching is performed in correspondence with each soldered portion, a lot of time is required in the manufacturing process, and the production efficiency of the substrate 2 is lowered. There is a problem that leads to. Specifically, as shown in the time chart of FIG. 4, when starting soldering, the soldering conditions are set by instructing the laser start after moving the laser head from the standby position to the laser irradiation position. It is assumed that it will be done. In this case, as shown by T1 and T2 in the figure, the solder supply control device and the laser control device receive the soldering conditions from the main control device side of the equipment, and the time T1 for switching to the corresponding control parameters, respectively. Requires T2. Therefore, even if the laser beam irradiation is started immediately after the control parameter setting is completed, it takes time (T1 + T2 + T3) from the laser start instruction to the completion of soldering, which is a factor that lowers the production efficiency of the substrate 2. Become.

Therefore, in this equipment 15, as shown as "condition switching" in FIGS. 2 and 3, while setting appropriate soldering conditions corresponding to each soldered portion, the production efficiency is reduced due to this. It is supposed to be suppressed. The configuration will be described in detail with reference to FIGS. 2 and 3. Here, FIG. 2 shows the flow of processing when one soldered portion is present on one substrate 2 for convenience of explanation, and also for supplying the solder material in the moving step of the laser head 10. The relevant control parameters shall be switched. Further, A1 to A11, B1 to B5, and C1 to C3 in FIG. 2 represent each step, the carry-in means including the carry-in belt is a "carry-in device", and the carry-out means including the carry-out belt is a "carry-out device". To simplify the explanation.

That is, first, when the main control device 16 of the equipment 15 starts the process of FIG. 2, in the carry-in process, the substrate 2 is put into the machine by the carry-in device and set on the set surface 11a (A1). At this time, in the substrate 2, the terminal 3a of the electronic component 3 inserted into the through hole 4 and arranged so as to project as shown in FIG. 1 and the land 5 are used as soldering portions.

Next, the main control device 16 reads the coordinate data associated with the substrate 2 and the soldering conditions, controls the robot arm based on the coordinate data, and solders the laser head 10 from the standby position which is the original position. It is moved to the laser irradiation position corresponding to the attached portion (A2, A3).

Then, the main control device 16 executes a process for setting control parameters related to the supply of the solder material in the moving steps of A2 and A3 (A5 to A8). In this case, the main control device 16 collates the soldering conditions of the substrate 2 set this time, and when it is determined that the setting needs to be switched (A5), the soldering conditions are set (A6), and the supply control device Output to 18 (A7).

As a result, the supply control device 18 receives information related to the execution of switching of the soldering conditions (B1), and performs a setting step of switching to the soldering conditions (B2). In the setting step, at least one of the solder supply angle θ, the solder supply direction, the supply speed of the solder thread 12, and the like as control parameters related to the supply of the solder material is switched and set. In this way, when the condition switching is completed, the supply control device 18 outputs a condition switching completion signal to that effect to the main control device 16 on the equipment 15 side (B3).

When the main control device 16 receives the condition switching completion signal output from the supply control device 18 (A8) and determines that the movement of the laser head 10 to the laser irradiation position is completed (A4), the main control device 16 irradiates the laser beam. A control parameter related to the laser control device 17 is output to start the operation, and the supply control device 18 is instructed to supply the thread solder 12 in accordance with the irradiation of the laser beam (A9).

As a result, when the laser control device 17 receives an instruction of a control parameter related to laser light irradiation, a setting step of switching to the control parameter is performed (C1). In this setting step, at least one of the control parameters related to the irradiation of the laser beam such as the laser output and the irradiation time is switched and set.

When the setting of the soldering condition is completed, the laser control device 17 assumes that the soldering start condition is satisfied, generates a laser beam in the oscillating unit, and irradiates the laser head 10 from the laser head 10 (C2). In this soldering step, the laser beam is irradiated for a predetermined time with the output set for both the land 5 and the terminal 3a in the soldered portion as the irradiation region, and the solder thread 12 is set while being guided by the solder guide 13a. Soldering is performed by feeding out to the irradiation region at a predetermined speed from the supplied supply angle θ or the supply direction (B4).

In this way, when the irradiation of the laser beam is completed by the laser control device 17, the irradiation completion signal is output to the main control device 16 (C3), and when the supply of the solder thread 12 is completed by the supply control device 18, the supply completion signal is obtained. Is output to the main control device 16 (B5).
When the main control device 16 receives the irradiation completion signal from the laser control device 17 and the supply completion signal from the supply control device 18 (A10), the robot arm moves the laser head 10 to the in-situ position (A11). , The substrate 2 is carried out of the machine from the set surface 11a by the carry-out device (A12). In this way, when the main control device 16 completes the process of setting A1 to A12, B1 to B5, and C1 to C3 into one cycle (A13), the main control device 16 returns to the "start" of FIG. 2 to return to the other substrate 2. Can also be processed continuously.

During the moving steps of A2 to A4 described above, the conditions of both B2 and C1 may be switched. This specific configuration will be described with reference to the time chart of FIG. Here, t1 to t4 in FIG. 3 represent the time points from the start of movement to the completion of movement of the laser head 10, and t2 to t3 are the setting of control parameters in the supply control device 18 and the control parameters in the laser control device 17. It represents the time required for setting, and t4 to t5 represent the time required for soldering.

That is, the main control device 16 starts the process from the carrying-in process, sets the loaded substrate 2 on the setting surface 11a (A1 in FIG. 2), and starts the subsequent moving process, that is, at the time point of t1 in FIG. Then, the laser head 10 is moved from the original position to the laser irradiation position based on the coordinate data associated with the substrate 2 (A2, A3).

During this moving step, the main control device 16 sends control parameters related to the supply of the solder material to the supply control device 18 in order to perform the soldering condition setting steps (A5 to A9, B1 to B3, C1) in parallel. At the same time as outputting (t2 in FIG. 3), the control parameters related to the irradiation of the laser beam are output to the laser control device 17 (t2 in the same). As a result, it is possible to perform a setting step of switching to the control parameter received by the supply control device 18 and a setting step of switching to the control parameter received by the laser control device 17 from the movement process.

After that, the condition switching completion signal is output to the main control device 16 as the setting process is completed in the supply control device 18, and the condition switching completion signal is output to the main control device 16 as the setting process is completed in the laser control device 17. Output.

Here, the main control device 16 determines that the condition switching is completed at the time of t3 when the condition switching completion signal is received from both the supply control device 18 and the laser control device 17. Further, as illustrated in FIG. 3, it is assumed that the start condition is satisfied in the main control device 16 at the time after t3 and at the time of t4 when the movement of the laser head 10 to the laser irradiation position is completed. , That is, the laser control device 17 is instructed to start irradiating the laser beam, and the supply control device 18 is instructed to start the supply of the thread solder 12, so that the soldering process is performed.

After that, the main control device 16 uses the laser head 10 at the time of t5 when the soldering process is completed and the irradiation completion signal from the laser control device 17 and the supply completion signal from the supply control device 18 are received. While moving to the position, the substrate 2 is carried out from the set surface 11a to the outside of the machine, and this process is completed.

In addition, in FIGS. 2 and 3, the case where one board 2 has one soldering part was described as an example, but the same laser is also used when one board 2 has a plurality of soldering parts. It is possible to process by the soldering method. Specifically, for example, even if the first soldering part, the second soldering part, ... The twelfth soldering part exist on one board 2, and the soldering conditions are different in each soldering part, the figure is shown. The processing of A1 to A10, B1 to B5, C1 to C3 of 2 or the processing described in the time chart of t1 to t5 of FIG. 3 can be executed for each soldered portion according to the above-mentioned order data.

As described above, the laser soldering method of the present embodiment includes a moving step of moving the laser head 10 relative to the substrate 2 to a position where soldering is performed, and individual soldering destinations in the moving step. Start soldering when the setting process for setting the soldering conditions related to soldering by laser beam, which is the soldering conditions corresponding to the attached part, and the soldering conditions corresponding to the soldered part are set. Assuming that the start condition is satisfied, a soldering step of irradiating a laser beam to perform soldering is provided, and by setting the soldering condition from the moving step, the moving step and the setting step are performed in parallel. The start condition includes the completion of the relative movement to the position where the soldering is performed.

According to this, it is possible to set the soldering conditions corresponding to each soldering portion in the setting process, and it is possible to set the soldering conditions and the relative movement of the laser head 10 in parallel. The time can be shortened as compared with the case where the soldering conditions are set after the relative movement of the laser head 10.
Further, since the start condition includes the completion of the relative movement of the laser head 10 to the position where the soldering is performed, the timing is suitable without causing a problem such as irradiating the laser beam during the relative movement of the laser head 10. Soldering can be started at, and a reliable connection can be made as a whole.

The equipment 15 is configured to irradiate a laser beam and start soldering when the relative movement of the laser head 10 to the soldering position is completed and the setting of the soldering conditions is completed. There is. Therefore, for example, the time can be shortened as much as possible regardless of the length of the setting process time of t2 to t3 with respect to the moving process time of t1 to t4 in FIG.

The soldering conditions include control parameters related to irradiation of laser light and control parameters related to supply of solder material to the soldered portion. Therefore, each control parameter can be set during the moving process, and the times T1 and T2 described in FIG. 4 can be shortened.

Further, when a plurality of soldering conditions are set corresponding to a plurality of soldered portions on one substrate 2, it is possible to significantly reduce the time in the manufacturing process of the substrate 2 and improve the production efficiency. ..

Although the present disclosure has been described in accordance with Examples (Embodiments), it is understood that the present disclosure is not limited to the Examples and structures. The present disclosure also includes various variations and variations within a uniform range. In addition, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are within the scope and scope of the present disclosure.
For example, the number of soldered portions, soldering conditions, and the like on the substrate 2 are not limited to the above-mentioned number and control parameters, and can be changed as appropriate.

In the drawings, 1 is a laser soldering device, 2 is a substrate, 3a is a terminal (soldered portion), 5 is a land (soldered portion), and 10 is a laser head.

Claims (4)

This is a laser soldering method in which the soldered portion of the substrate (2) to be soldered is soldered by irradiating the soldered portion with a laser beam from the laser head (10).
A moving step of moving the laser head relative to the substrate to a position where soldering is performed, and
A setting step for setting soldering conditions for soldering by the laser beam, which is a soldering condition corresponding to each soldering portion to be moved to in the moving step, and a setting step.
When the soldering condition corresponding to the soldered portion is set, the soldering step of irradiating the laser beam to perform the soldering is provided, assuming that the start condition for starting the soldering is satisfied. ,
By setting the soldering condition from the moving step, the moving step and the setting step are performed in parallel, and the relative movement to the position where the soldering is performed is completed as the start condition. Laser soldering method. The laser solder according to claim 1, wherein when the relative movement of the laser head to the soldering position is completed and the setting of the soldering conditions is completed, the laser light is irradiated and the soldering is started. How to attach. The laser soldering method according to claim 1 or 2, wherein the soldering condition includes a control parameter related to irradiation of the laser beam and a control parameter related to supply of the solder material to the soldered portion. The laser soldering method according to any one of claims 1 to 3, wherein the plurality of soldering conditions are set corresponding to the plurality of soldered portions on the same substrate.

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