JP6147793B2 - Laser module - Google Patents

Description

The present invention relates to a laser module, and more particularly to a laser module configured to obtain a high-power laser by combining lasers emitted from a plurality of LDs (laser diodes).

  Lasers are used in various fields such as a material processing field represented by metal and a medical field by utilizing the high energy density. Particularly in the field of material processing, the output of lasers has been increased for the purpose of shortening the processing time.

  One type of laser used in the field of material processing includes a structure called DDL (Direct Diode Laser). Hereinafter, DDL will be briefly described.

DDL uses a module that combines multiple LDs as described in Patent Document 1, and combines each laser beam emitted from each LD into a single laser beam using a condensing member such as a lens. In this method, the object to be processed is directly irradiated. In order to increase the output of DDL, the number of LDs used should be increased.

In DDL, all the LDs or LD groups to be used are divided into a plurality of groups, and the LDs belonging to each group are electrically connected in series to supply a drive current in many cases.
This is because the laser output of the LD depends on the value of the current flowing through the LD. In order to make the output of each LD uniform, a series connection that can supply an equal current to each LD is employed.

However, in the laser module described in Patent Document 1, in order to connect each LD in series, the polarity of the LD is changed between the odd-numbered column and the even-numbered column. For this reason, it is necessary to manage the polarity in managing the parts used in the laser module.
If the number of LDs is increased to increase the output of the laser module, this management becomes complicated.

In addition, since the appearance is similar even if the polarity is reversed, it takes time to confirm the polarity in the assembly process of the laser module, and there is a possibility that the assembly is performed using the LD of the wrong polarity.

In addition, it is necessary to design and manufacture other parts so as to cope with the polarity direction of the two types of LDs, and problems such as complicated management and an increase in design cost due to an increase in the number of parts occur. .

JP 2007-142439 A

An object of the present invention is to provide a laser module in which the polarities of LDs used can be unified and the above-described problems caused by the difference in polarity are eliminated.

As a result of intensive studies on the configuration of the laser module, the inventor has found that an electrode existing on one end side of the LD unit installed on one end side of the mounting surface of an arbitrary stage of the heat sink, and a mounting surface on the lower side of the arbitrary stage It has been found that the above problem can be solved by adopting a structure in which an electrode existing on the other end side of the LD unit installed on the other end side is electrically connected by a conductive member.

The laser module of the present invention is a laser module composed of a heat sink having a plurality of stepped mounting surfaces and a plurality of LD units installed on the mounting surface,
The LD unit is configured by providing at least one LD on a unit base,
The LD unit is mounted on the mount surface so that the laser light emitted from the LD unit installed on the upper mount surface of the heat sink is not blocked by the LD unit installed on the lower mount surface of the heat sink. And installed in
An electrode present on the one end side of the LD unit installed on one end side of the mount surface of an arbitrary step of the heat sink, and the LD unit installed on the other end side of the mount surface lower than the arbitrary step The electrode existing on the other end side is electrically connected by a conductive member.

The laser module of the present invention has the following excellent effects.

-All the polarities of the LD and LD unit to be used can be unified.

・ Polarity management and confirmation are no longer necessary, eliminating these steps and eliminating the risk of assembly of the laser module with incorrect polarity.

・ Since LD units with the same design can be used, design costs can be reduced.
By producing a plurality of identically designed products, it is possible to aim for a cost reduction effect.

As a result, when obtaining a high-power laser module with an increased number of LD units, a product with excellent productivity and cost can be obtained.

It is a reference example of the present invention. It is an example of the heat sink used for this invention. It is an example of LD unit used for the present invention. It is an example of LD used for this invention. This is a method of connecting adjacent LD units. It is explanatory drawing of the positional relationship of a conductive member accommodating part, a cooling pipe, and LD. It is an Example of this invention. It is a specific example of the connection method of adjacent LD units.

Hereinafter, embodiments of the laser module of the present invention will be described with reference to FIG. FIG. 1 shows the present invention in the case where LD units are provided in two horizontal rows and five vertical rows on a heat sink. The number of columns may be increased or decreased depending on the desired laser module output.

In FIG. 1, 1 is a heat sink, 2 is an LD unit, 6a and 6b are electrodes, and 7 is a conductive member.
What is characteristic of the present invention is that the electrode 6a existing on one end side of the LD unit 2 installed on one end side of the mounting surface of an arbitrary stage of the heat sink 1 and the mounting surface on the lower stage side of the arbitrary stage. That is, the electrode 6 b existing on the other end side of the LD unit 2 installed on the end side is electrically connected by the conductive member 7.

  An electrode 6a existing on one end side of the LD unit 2 installed on one end side of the mounting surface of an arbitrary step of the heat sink 1, and an LD unit 2 installed on the other end side of the mounting surface below the arbitrary step By electrically connecting the electrodes 6b existing on the other end side of each of them by the conductive member 7, they can be connected in series with the polarities of the LD units 2 being unified.

  Since the polarity of each LD unit 2 can be unified, it is possible to prevent a mistake that the LD unit 2 is attached with the wrong polarity when the LD unit 2 is installed on the mounting surface of the heat sink 1. In addition, since it is not necessary to pay attention to the direction of polarity during assembly, the productivity of assembly work is also improved. In addition, since it is not necessary to classify and manage the LD unit 2 according to polarity, labor can be reduced in terms of component management.

  As the conductive member 7, a wire in which an electric conductor is coated with an insulating material and a connection terminal is usually used. If necessary, other conductive members such as a metal plate may be used. When the conductive member comes into contact with other parts constituting the laser module and the operation is affected, an appropriate insulating material may be provided.

FIG. 2 shows an example of the heat sink 1 used in the present invention.
As a whole, it is formed in a staircase shape, and a mount surface for installing the LD unit is formed in each step. The level difference is set to a height at which the laser light emitted from the LD unit 2 installed on the upper mount surface is not blocked by the LD unit 2 installed on the lower mount surface.

As the material of the heat sink 1, a material such as copper or aluminum having excellent thermal conductivity may be used.

FIG. 3 shows an example of the LD unit 2 used in the present invention. The LD unit 2 has a configuration in which at least one LD 5 is provided on the unit base 3.
FIG. 3 shows a case where three LDs 5 are provided, and the LD 5 is provided on the unit base 3 via the LD base 4. The LD pedestal 4 may be molded integrally with the unit pedestal 3 or may be configured as a separate part. The LD 5 is insulated from the unit base 3.

  An example of the LD 5 used in the present invention is shown in FIG. The LD 5 has a configuration in which an LD element and a positive electrode and a negative electrode for supplying current for driving the LD element are provided on a submount. This configuration is an example, and the LD 5 used in the present invention may take other configurations within the scope of the technical idea of the present invention.

As the material for the unit base 3 and the LD base 4, a material such as copper or aluminum having excellent thermal conductivity may be used.

When a plurality of LDs 5 are provided in the LD unit 2, the LDs 5 are connected in series with bonding wires (not shown) in the LD unit 2. Further, the LD unit 2 is provided with an electrode 6 and is used for electrical connection with the adjacent LD unit 2 on the mount surface, the conductive member 7, or a power supply device for driving the LD. The electrode 6 is insulated from the LD base 4.

Normally, as shown in FIG. 3A, the electrode 6 may be provided adjacent to the LD 5 existing on one end side and the other end side of the LD unit 2 and connected by a bonding wire. Within the scope of the technical idea, aspects such as the position and shape of the electrode 6 may be appropriately changed.
For example, as shown in FIG. 3B, the positive electrode or the negative electrode included in the LD 5 can be directly used as the electrode 6.

Usually, the LD unit 2 is provided with a collimating lens for collimating the laser light emitted from the LD 5.
As the collimating lens, a fast axis direction collimating lens 8 and a slow axis direction collimating lens 9 are generally provided as shown in FIG.
The laser light is transmitted through the fast axis collimating lens 8 and the slow axis collimating lens 9 and collimated to combine the laser light emitted from each LD unit into one by the condenser lens. The diameter of the laser beam can be prevented from increasing carelessly and the energy density can be prevented from decreasing.

The fast axis direction collimating lens 8 may be provided with a common lens for each LD 5 as shown in FIG. 3A, or may be provided individually for each LD 5 as shown in FIG. A lens may be provided.
The slow axis direction collimating lens 9 is also provided individually for each LD 5 in FIG. 3, but a common lens may be used for each LD 5.

For electrical connection between the adjacent LD units 2 on the same mounting surface of the heat sink 1, a conductor plate having a predetermined shape called a contact 10 is used as shown in FIG.
Both ends of the contact 10 are respectively connected to the electrodes 6 and the adjacent LD units 2 are electrically connected.
FIG. 5A shows an example of how to provide the contact 10 when the electrode 6 is provided as an independent component, and FIG. 5B shows an example of how the contact 10 is provided when the positive electrode and the negative electrode of the LD 5 are used as the electrode 6.

  When the adjacent LD units 2 are electrically connected using the contact 10, it is preferable to provide the auxiliary contact 11 on the contact 10. The auxiliary contact is a component having a function of increasing the electric capacity of the contact 10.

As the auxiliary contact 11, a conductive material having a certain volume, such as a metal block, can be used. By bringing the contact 10 and the auxiliary contact 11 into electrical contact, it can be considered that the volume of the contact 10 has increased, and as a result, the electrical capacity of the contact 10 increases.

When driving a high-power laser module, the drive current also becomes a large current. By providing the auxiliary contact 11 and increasing the electric capacity, a large current can flow stably, and the operation of the laser module is stabilized.
Further, heat generation in the contact 10 caused by a large current can be suppressed.

As the heat sink 1 used in the present invention, it is preferable to use the heat sink 1 provided with the conductive member accommodating portion 12 on the mount surface as shown in FIG.
By providing the conductive member accommodating portion 12 in the heat sink 1 and accommodating a part of the conductive member 7 in the conductive member accommodating portion 12 in the middle of connecting the one end side electrode 6a and the other end side electrode 6b, the following effects are obtained. can get.

Compared with the case where the conductive member 7 is provided so as to straddle the LD unit group, the height dimension can be suppressed, which can contribute to the miniaturization of the laser module.
In addition, it is possible to prevent the conductive member 7 from being accidentally changed in position and being irradiated with laser light and being damaged.

When the conductive member accommodating portion 12 is provided on the heat sink 1, it is preferable to provide the conductive member accommodating portion 12 at a position that does not overlap with the LD 5 when the laser module is viewed from above, as shown in FIG.
Although the LD 5 serves as a heat source during laser irradiation, the heat transfer distance between the LD 5 and the surface of the heat sink 1 can be shortened and a heat transfer area can be increased by setting the conductive member housing portion 12 at this position. Therefore, the heat radiation of the LD 5 can be performed efficiently.

  Furthermore, in order to promote the heat radiation of the LD 5, it is preferable to form a cooling pipe 13 for flowing the refrigerant in the heat sink 1. By cooling the heat sink 1 with the refrigerant, the heat radiation of the LD 5 can be performed more efficiently.

When the cooling tube 13 is formed, the position of the cooling tube 13 is preferably provided at a position overlapping the LD 5 when the laser module is viewed from above, as shown in FIG.
By setting the cooling pipe 13 to this position, the distance between the LD 5 and the cooling pipe 13 is shortened, and the heat dissipation of the LD 5 can be performed more efficiently.

When it is difficult to provide the cooling pipe 13 directly on the heat sink 1, a structure in which the heat sink 1 is installed on a cooling plate provided with the cooling pipe 13 may be used. Even in this case, the cooling tube 13 is preferably provided at a position overlapping the LD 5 when the laser module is viewed from above.

  As an example of the present invention, a laser device was produced that used the laser module of the present invention shown in FIG.

As the LD unit 2, a unit using three LDs 5 shown in FIG. 3 is used.
A commercially available LD5 having a wavelength of 915 nm, an output of 12 W, and a consumption voltage of 1.8 V was used, and the laser output per LD unit 2 was set to 36 W and the consumption voltage was 5.4 V.

A first cylindrical lens is provided as the fast axis collimating lens 8 in the immediate vicinity of the exit surface of the LD group provided in the LD unit 2, and a second cylindrical lens is provided as the slow axis collimating lens 9 on the surface of the unit base 3. Provided.
That is, the laser light emitted from the LD 5 is collimated through the fast axis collimating lens 8 and then through the slow axis collimating lens 9.

  Electrodes 6 for supplying a current for driving the LD 5 were provided at both ends of the LD base 4.

A laser module that outputs a laser beam of 2.448 kW is calculated using 68 LD units 2 configured as described above. As the heat sink 1 on which the LD unit 2 is provided, a heat sink having 17 stepped mount surfaces on which LD units can be arranged in four horizontal rows is used. The material of the heat sink 1 was copper.

When the LD unit 2 is provided, the step on the mounting surface of the heat sink 1 is set to a height at which the LD unit 2 provided on the lower stage side does not block the laser light emitted by the LD unit 2 provided on the upper stage side.

Grooves were provided as conductive member accommodating portions 12 on each mount surface other than the lowermost stage of the heat sink 1.
The position of the groove was provided in front of each mount surface so that it would not overlap with the LD 5 when the laser module was viewed from above.

The heat sink 1 is also provided with a cooling pipe 13 for flowing a coolant that promotes cooling of the LD 5.
Four cooling tubes 13 are provided from the back of the heat sink 1 toward the front so that the cooling modules 13 may overlap with the LD 5 when the laser module is viewed from above.
The cooling pipe 13 is connected to a pump that continuously supplies the refrigerant.

  An electric wire was accommodated as the conductive member 7 in the groove provided in the heat sink 1. In consideration of heat generation during LD driving, the wires used were conductors coated with silicone rubber with high heat resistance. Moreover, the terminal used for a connection with the electrode 6 was provided in the both ends of the electric wire.

After the electric wire was accommodated in the groove, the LD unit 2 was fixed to the mount surface.
For fixing the LD unit 2 to the mount surface, a screw hole was previously provided in the mount surface, and through holes (both not shown) through which the fixing screw was passed through the unit base 3 were used.

Adjacent LD units 2 were electrically connected by contacts 10 formed by processing a copper plate into a predetermined shape, and a copper block material was fixed on each contact 10 as an auxiliary contact 11 so as to be in electrical contact.

A specific method for fixing the contact 10 and the auxiliary contact 11 used in the embodiment is shown in FIG.
This fixing method is not shown in FIG.
The mounting surface (heat sink 1) was previously provided with a screw hole, and the contact 10 and the auxiliary contact 11 were provided with a through-hole through which a fixing screw was passed, and fixed by screw fixing. In addition, in order to prevent a short circuit with the fixing screw, the through hole is subjected to insulation treatment.

In order to prevent the contact 10 and the heat sink 1 from being short-circuited by an unexpected foreign matter or the like, a ceramic ring is provided as an insulator between the contact 10 and the heat sink 1.
Further, in order to prevent a short circuit between the head of the fixing screw and the auxiliary contact 11, a ceramic ring was provided as an insulator between them.

  The method of fixing the contact 10 and the auxiliary contact 11 shown in FIG. 8 is an example, and other fixing methods may be used.

  When the fixing of the contact 10 and the auxiliary contact 11 is completed, as shown in FIG. 7, the mount in which the LD unit 2 is installed on the electrode 6 on the A end side of the LD unit 2 installed on the A end side of the mount surface. The terminal of the electric wire accommodated in the groove on the surface is connected, and the electrode on the B end side of the LD unit 2 installed on the B end side of the lower mounting surface is accommodated in the groove on the upper mounting surface. The terminal of the electric wire was connected, and the LD unit 2 installed in each stage was electrically connected in series.

  Two power supply devices (not shown in FIG. 7) for driving the LD unit 2 having a voltage of 200V are used, each of which is a group of LD units installed on the mount surface for the upper 9 stages and the lower 8 The laser module was completed by connecting to the LD unit group installed on the mounting surface for the steps and configuring the upper side and the lower side as separate electric systems.

The reason why the electric system is divided between the upper stage side and the lower stage side is that when all the LD units 2 to be used are connected in series, the consumption voltage becomes 367.2V, and the voltage of the power supply device of 200V becomes insufficient.
Although a mode in which all the LD units 2 are connected in series is possible by raising the voltage of the power supply device, in the embodiment, in consideration of ease of handling of the power supply device, a mode in which two 200 V power supply devices are used is used. I took it.

  The laser module completed as described above is housed in a housing having a condensing lens, and each laser beam irradiated from the LD unit group is configured to be condensed at one point by the condensing lens, The laser device was completed.

The laser device was driven while flowing water as a coolant through the cooling pipe 13, and the output of the laser beam emitted from the device was measured, and it was confirmed that an output of 2.2 kW was obtained. Although it is an output of 2.448 kW in calculation, considering a loss of output in an actual use environment such as a part of the output being absorbed when passing through the lens, it is a laser device that outputs a laser beam of 2 kW class. It can be said that the necessary and sufficient output was obtained.

  In addition, it was also confirmed that the operation and output were stable without excessive heating of the LD 5 and the laser module during driving of the laser device.

  As described above, according to the present invention, it is possible to obtain a laser module that is excellent in productivity and has necessary and sufficient performance.

The laser module of the present invention can be used for various laser devices that require a structure in which a plurality of LD units are arranged in a step shape, including a laser device for material processing.
In the above description, the case where a plurality of LD units are installed on the mounting surface of each stage of the heat sink has been described. However, the present invention can be applied even when there is one LD unit installed on the mounting surface of each stage. Can do.

1 Heat Sink 2 LD Unit 3 Unit Base 4 LD Base 5 LD (Laser Diode)
6 Electrode 6a One end side electrode 6b The other end side electrode 7 Conductive member 8 Fast axis collimating lens 9 Slow axis collimating lens 10 Contact 11 Auxiliary contact 12 Conducting member accommodating portion 13 Cooling pipe

Claims (4)

A laser module comprising a heat sink having a plurality of step-shaped mounting surfaces and a plurality of laser diode (LD) units installed on the mounting surface,
The LD unit is configured by providing at least one LD on a unit base,
The LD unit is mounted on the mount surface so that the laser light emitted from the LD unit installed on the upper mount surface of the heat sink is not blocked by the LD unit installed on the lower mount surface of the heat sink. And installed in
An electrode present on the one end side of the LD unit installed on one end side of the mount surface of an arbitrary step of the heat sink, and the LD unit installed on the other end side of the mount surface lower than the arbitrary step The electrode on the other end side is electrically connected by a conductive member ,
Part of the conductive member is not overlapped with the laser diode when the laser module is viewed in plan from directly above while connecting the electrode existing on the one end side and the electrode existing on the other end side. The laser module is housed in a conductive member housing provided on the mount surface of the heat sink. A cooling pipe for flowing a refrigerant is formed in the heat sink,
Item 2. The laser module according to Item 1. 2. The laser module according to claim 1, wherein the heat sink is installed on a cooling plate on which a cooling pipe for flowing a refrigerant is formed. 4. The laser module according to claim 2, wherein the cooling pipe is provided at a position overlapping with the laser diode when the laser module is viewed from above.

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