JP7277811B2 - laser device - Google Patents

Description

The present invention relates to laser devices.

As a method of supplying electric power to a laser element, a method of connecting a laser element and a relay member with a wire and connecting a lead terminal and a relay member with another wire is known (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2003-101085

Thereby, the laser element and the lead terminals can be electrically connected without directly connecting the laser element and the lead terminals with a single wire. However, the laser device described in Patent Document 1 has room for making the wire less likely to be cut.

A package having a base provided with two or more through holes, two or more lead terminals inserted into the two or more through holes, and two or more laser elements arranged in the package. , one or two or more conductive relay members arranged in the package, and one of the two or more laser elements and the one relay member, or the two or more and a first wire connecting one of the laser elements and one of the two or more relay members, and the relay to which one of the two or more lead terminals and the first wire are connected. and a second wire shorter than the first wire, the laser device connecting the member to the member.

It is possible to provide a laser device in which wires are less likely to be fused.

1 is a schematic plan view showing a laser device according to an embodiment; FIG. FIG. 1B is a schematic cross-sectional view along line IB-IB in FIG. 1A. It is an enlarged view in FIG. 1A. 1 is a schematic perspective view showing a laser device according to an embodiment; FIG. FIG. 2B is an enlarged view of FIG. 2A; 1 is a schematic plan view showing a laser device according to an embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention, and do not specify the present invention. Furthermore, in the following description, the same names and symbols indicate the same or homogeneous members, and detailed description thereof will be omitted as appropriate.

[Embodiment]
As shown in FIGS. 1A and 2A, in the laser device 100 according to the present embodiment, two or more through holes are provided in the base body 11 of the package 10, and two or more through holes are formed in the two or more through holes. A lead terminal 14 is inserted. Two or more laser elements 20 and one or two or more conductive relay members 30 are arranged in the package 10 . In this embodiment, the laser element 20 is arranged in the package 10 via the submount 21 . Here, the first wire 41 connects one of the two or more laser elements 20 and one relay member 30, or connects one of the two or more laser elements 20 and two or more and one of the relay members 30 of . A second wire 42 connects one of the two or more lead terminals 14 and the relay member 30 to which the first wire 41 is connected. And the second wire 42 is shorter than the first wire 41 . A relay member 30 to which both the first wire 41 and the second wire 42 are connected is called a relay member 30a, and the wires 40 other than the first wire 41 and the second wire 42 are connected. The relay member 30 is called a relay member 30b. Among the laser elements 20, the laser element 20 connected to the relay member 30a by the first wire 41 is called a laser element 20a, and the other laser elements 20 are called laser elements 20b.

The limit current value when the wire for connecting desired members is fused (hereinafter referred to as "fusion current value") can be calculated based on the specifications such as the wire member, diameter, and length. can. The larger the wire diameter, the higher the fusing current value, and the shorter the wire length, the higher the fusing current value. Therefore, in order to confirm the correlation between the calculated values and the measured values, the inventors connected desired members with wires and measured the fusing current values of the wires. As a result of measuring by changing the type of connecting member, the fusing current value of the wire may be lower than the calculated value depending on the type of the member to which the wire is connected, even if the wire of the same specification is used. have understood. It is considered that the main cause of this is that the temperature of the member to which the wire is connected rises, and the heat of the member is transmitted to the wire. That is, when calculating the wire fusing current value, the current value at which the wire temperature reaches the melting point of the wire is taken as the fusing current value based on the amount of heat generated when a predetermined current value is passed through the wire. However, it is thought that the temperature of the wire reached the melting point of the wire at a current value lower than the calculated value because the heat of the member was transferred to the wire due to the temperature rise of the member connected to the wire.

Therefore, for example, even if two wires with the same specifications are prepared and the same current value is applied to each wire, the wire connected to a member that tends to become relatively hot is relatively less likely to become hot. It is easier to melt than the wire connected to the member.

Therefore, in the package 10 of the present embodiment, the fusing current value of the wire 40 connecting the lead terminal 14 and the relay member 30 is measured, and the fusing current value of the wire 40 connecting the laser element 20 and the relay member 30 is measured. It was measured. Note that the wire 40 of the same specification was used in each measurement here as well. As a result, the fusing current value of the wire 40 connecting the lead terminal 14 and the relay member 30 was 5.5 A, and the fusing current value of the wire 40 connecting the laser element 20 and the relay member 30 was 5.9 A. . That is, the fusing current value of the wire 40 connecting the lead terminal 14 and the relay member 30 is smaller than the fusing current value of the wire 40 connecting the laser element 20 and the relay member 30 . It is considered that the main cause of this is that the lead terminal 14 has become hotter than the laser element 20 . That is, when the package 10 of this embodiment has a structure in which the lead terminals 14 are inserted into the through holes of the base 11 , most of the lead terminals 14 are exposed from the base 11 . Such exposed portions come into contact with air and gases within the package 10, but these gases have relatively low thermal conductivity. Moreover, although a part of the lead terminal 14 is in contact with the base 11 , the contact area between the lead terminal 14 and the base 11 is relatively small. A connector (not shown) can be connected to the lead terminal 14 in order to supply power to the laser element 20. However, since the contact area between the lead terminal 14 and the connector is relatively small, heat is difficult to dissipate to the connector. Therefore, in the package 10 of the present embodiment, heat accumulated in the lead terminals 14, and it is considered that the fusing current value of the wires 40 connecting the lead terminals 14 and the relay member 30 was lower than the calculated value.

Although the temperature of the laser element 20 also rises, the laser element 20 is arranged on the substrate 11 via the submount 21 . Therefore, the heat from the laser element 20 is radiated to the substrate 11 via the submount 21 over substantially the entire lower surface of the laser element 20 . Further, the lower surface of the base 11 is a flat surface, and substantially the entire surface can be thermally connected to an external heat dissipation member such as a heat sink (not shown). On the other hand, since the lead terminal 14 is provided on the side wall of the substrate 11, the distance to such a heat dissipation member is relatively large. Therefore, in the package 10 of the present embodiment, the laser element 20 is less likely to accumulate heat and reach a higher temperature than the lead terminals 14 . As a result, it is considered that the fusing current value of the wire 40 connecting the laser element 20 and the relay member 30 did not decrease much compared to the fusing current value of the wire 40 connecting the lead terminal 14 and the relay member 30. .

Therefore, as shown in FIGS. 1A, 1C, 2B, etc., the second wire 42 is made shorter than the first wire 41 in the package 10 of the present embodiment. As a result, even if the fusing current value of the second wire 42 decreases due to the heat from the lead terminal 14, which tends to reach a relatively high temperature, the fusing of the second wire 42 can be made difficult. As a result, it is possible to reduce the possibility that the laser device 100 is opened due to the fusing of the second wire 42 .

Each member will be described below.

(package)
As shown in FIGS. 1A and 2A, the package 10 has a base 11 provided with two or more through holes, and two or more lead terminals 14 inserted into the two or more through holes. In this embodiment, the base 11 has a base 12 and a frame 13 fixed to the upper surface of the base 12 . Two or more laser elements 20 and one or two or more relay members 30 are arranged on the upper surface of base 12 inside frame 13 . Through holes are provided in two opposing side walls of the four side walls that constitute the frame 13, and the lead terminals 14 are inserted so as to close the through holes. In this embodiment, one side wall of the two opposing side walls is provided with four through holes each, and lead terminals 14 are inserted into the respective through holes. Copper or the like can be used as the base 12 . By using a material having a relatively high thermal conductivity for the base 12, the heat from the laser element 20 can be easily dissipated. As the frame 13, iron, an iron-nickel alloy, or the like can be used. By using such a material whose surface is plated, as shown in FIG. 3, a lid body 50 and a frame body 13, which will be described later, can be fixed by welding. As a result, the space formed by the lid 50 and the package 10 can be easily hermetically sealed. For these reasons, it is preferable that the base 12 and the frame 13 are made of different materials. The base 12 and the frame 13 may be made of the same material. Further, as shown in FIG. 2A, the frame body 13 may have a structure including, for example, a main body portion 13a and a plate-like portion 13b having a greater thickness than the main body portion 13a and to which the lead terminal 14 is fixed. can be done.

Kovar, an iron-nickel alloy, or the like can be used as the lead terminal 14 . As a result, the thermal expansion coefficient of the lead terminals 14 becomes close to the thermal expansion coefficient of glass that can be used as an insulating member for the lead terminals 14, and the hermetic sealing of the package 10 can be easily ensured. The length of the lead terminal 14 can be 5 mm to 12 mm. This makes it easier to connect the lead terminal 14 and the relay member. The diameter of the lead terminal 14 can be 200 μm to 1000 μm, preferably 500 to 700 μm. This range is suitable for passing a large current of 2 A or more. The lead terminal 14 is fixed to the base 11 via an insulating member such as glass. The contact area between the lead terminal 14 and the insulating member can be 5% to 20% of the surface area of the lead terminal 14 . This range makes it difficult for the heat from the lead terminals 14 to radiate to the base 11, but reduces the possibility that the hermetic sealing of the package 10 is broken due to the difference in thermal expansion coefficient between the lead terminals 14 and the insulating member. be able to. That is, since the contact area between the lead terminals 14 and the insulating member can be made relatively small, the package 10 can be maintained at a higher temperature than when the contact area between the lead terminals 14 and the insulating member is relatively large. A hermetic seal can continue to be ensured.

(laser element)
Two or more laser elements 20 are arranged in the package 10, as shown in FIGS. 1A and 2A. In this embodiment, the laser element 20 is arranged on the upper surface of the base 12 inside the frame 13 . The number of laser elements 20 can be, for example, about 4-30. When the number of laser elements 20 is large, it is preferable to make the lower surface of the base 11 flat as in the package 10 of this embodiment. Thereby, the heat from the laser element 20 can be easily radiated. The laser elements 20 can be arranged in a matrix, for example. In this embodiment, the laser elements 20 are arranged in 5 columns and 4 rows. Although various laser elements can be used as the laser element 20, a GaN-based semiconductor laser element is used in this embodiment. A GaN-based semiconductor laser element can have an oscillation wavelength of, for example, 350 nm to 600 nm. When the GaN-based semiconductor laser device is combined with, for example, a YAG phosphor, the oscillation wavelength of the GaN-based semiconductor laser device can be preferably 430 nm to 460 nm. The GaN-based semiconductor laser device is preferably hermetically sealed in a package 10 because the laser light emitted by the GaN-based semiconductor laser device causes dust collection. On the other hand, in this case, since the gas filling the airtightly sealed space is less likely to flow, it is considered that the heat from the lead terminals 14 is less diffused into the gas than when not airtightly sealed. The power of each laser element 20 can be, for example, 0.5W to 10W, preferably 3W to 8W. In the case of a high-power laser element 20, a current value close to the fusing current value of the wire 40 may flow through the wire 40, so the wire 40 is particularly prone to fusing. The high-power laser device 20 is, for example, one with an output of 2 W or more. In this embodiment, the laser elements 20 arranged in each row are connected in series. The laser elements 20 arranged in two rows may be connected in series. The voltage applied to the laser elements 20 in each row can be, for example, 5V to 50V, preferably 15V to 30V.

The laser element 20 can be junction-down mounted in the package 10 . Here, the term "junction-down mounting" refers to mounting the main surface of the laser element 20 closer to the active layer on the upper surface of the substrate 11. For example, the active layer of the laser element 20 is less than half the thickness of the laser element 20. It means to mount so that it is on the bottom side. As a result, the heat generated by the laser element 20 can be effectively dissipated to the package 10 . In particular, heat can be effectively dissipated to the package 10 in the high-power laser device 20 as in this embodiment.

In this embodiment, as shown in FIG. 1B, the laser element 20 is arranged on the base 12 via the submount 21 . That is, the submount 21 is arranged on the upper surface of the base portion 12 and the laser element 20 is arranged on the upper surface of the submount 21 . As the submount 21, for example, a metal material such as iron, an iron alloy, or copper, or AlN, SiC, SiN, or the like having electric wiring formed on the upper surface thereof can be used. AlN is used as the submount 21 in this embodiment. The thickness of the submount 21 can be, for example, 0.2 mm to 0.5 mm. The submount 21 can have a side length of 0.5 mm to 2 mm on the lower surface. With this range, the heat from the laser element 20 can be effectively radiated to the base 12 via the submount 21 .

As shown in FIG. 3, when the laser element 20 is hermetically sealed, a lid body 50 is welded to the side wall of the base body 11. The lid body 50 consists of a support portion 50a containing metal for welding, and a support portion 50a. and an inner translucent portion 50b. Therefore, when viewed from above, the supporting portion 50a is arranged on the side wall of the base 11 and its vicinity. Since the support portion 50a has a lower transmittance with respect to laser light than the transparent portion 50b, the laser element 20 is preferably arranged at a position spaced apart from the side wall of the substrate 11 to some extent. Specifically, the laser element 20 is preferably arranged inside the tip of the lead terminal 14 when viewed from above. The shortest distance from the inner wall of the substrate 11 to the laser element 20 in top view is approximately 2 to 7 mm.

As shown in FIG. 1A, when two or more laser elements 20 are arranged along the extending direction of the lead terminals 14, the direction of the resonator of the laser elements 20 is the direction substantially orthogonal to the extending direction of the lead terminals 14. preferably. As a result, the wires 40 that electrically connect the laser elements 20 can be arranged at positions that do not block the laser beams emitted by the laser elements 20 . The two or more laser elements 20 each emit laser light, and the laser light is emitted upward directly or via a reflecting member 22 or the like. In this embodiment, as shown in FIGS. 1A, 1B, and 2A, a plurality of reflecting members 22 for reflecting laser light upward are arranged on the upper surface of the base 12 inside the frame 13. . The reflective member 22 can be, for example, a triangular prism, a truncated square pyramid, or the like having a reflective film formed on an inclined surface of glass. The slope on which the reflective film is formed in this manner can be used as a reflective surface that reflects the light from the laser element 20 upward. In this embodiment, light emitted from two or more laser elements 20 is reflected upward by a plurality of reflecting members 22 facing each laser element 20. If 20 emits light directly upward, the reflecting member 22 may not be arranged.

(Relay material)
As shown in FIGS. 1A and 2A , one or more conductive relay members 30 are arranged in the package 10 . In this embodiment, the relay member 30 is arranged on the upper surface of the base 12 inside the frame 13 . The relay member 30 is arranged adjacent to the side wall into which the lead terminal 14 is inserted. In other words, the relay members 30 are arranged at both ends of each row in which the laser elements 20 are arranged. Although two or more relay members 30 are arranged in the package 10 in this embodiment, the number of relay members 30 can be one. In this case, for example, the laser elements 20 can be arranged in one row, and the relay member 30 can be arranged at the left end of the row in which the laser elements 20 are arranged when viewed from above.

As the relay member 30, for example, a metal material such as iron, an iron alloy, or copper, or AlN, SiC, SiN, or the like having electric wiring formed on the upper surface thereof can be used. In this embodiment, AlN is used as the relay member 30 . The thickness of the relay member 30 can be, for example, 0.2 mm to 0.5 mm. The length of one side of the lower surface of the relay member 30 can be 0.5 mm to 2 mm.

The relay member 30 can dissipate heat from the wire 40 to the base portion 12 . Therefore, for example, for the wire 40 having the same specifications, the fusing current value of the wire 40 when connected to the lead terminal 14 and the relay member 30 is the same as that of the wire 40 when connected to the lead terminal 14 and the laser element 20. High compared to the fusing current value of 40.

A relay member 30 that is substantially the same as the submount 21 can be used. In other words, the relay member 30 and the submount 21 can be manufactured using the same material with the same dimensions as target values. As a result, the number of types of parts is reduced, and cost can be reduced. As shown in FIGS. 1A and 2A, the relay member 30 is spaced apart from the submount 21 . That is, the relay member 30 can be provided as a separate member from the submount 21 on which the laser element 20 is provided. Thereby, the heat from the wire 40 can be easily radiated to the base portion 12 via the relay member 30 . That is, when the relay member 30 also serves as the submount 21 on which the laser element 20 is mounted, the relay member 30 must dissipate not only the heat from the wire 40 but also the heat from the laser element 20 to the base portion 12. should not. By using separate members for the relay member 30 and the submount 21 , the relay member 30 can dissipate heat mainly from the wires 40 to the base portion 12 . Therefore, it is possible to suppress a decrease in the fusing current value of the wire 40 connected to the relay member 30 . The shortest distance from the relay member 30 to the lead terminals 14 can be made shorter than the shortest distance from the relay member 30 to the submount 21 . The shortest distance between the relay member 30 and the submount 21 can be about 0.1 to 4 mm. The shortest distance between the relay member 30 and the lead terminal 14 can be about 0.1 to 3.5 mm.

As shown in FIGS. 1A and 2A, for example, the relay member 30 and the submount 21 may be rectangular in shape when viewed from the top and have a longitudinal direction and a lateral direction. In this case, the relay member 30 is preferably arranged such that its longitudinal direction is substantially parallel to the extending direction of the lead terminals 14, and the submount 21 is disposed such that its lateral direction is substantially parallel to the extending direction of the lead terminals 14. It is preferable to arrange in the direction of As a result, the connection position on the relay member 30 of the wire 40 directed from the relay member 30 toward the laser element 20 can be made close to the laser element 20 . In other words, the wire 40 extending from the relay member 30 toward the laser element 20 can be shortened. Further, the submount 21 can have a longitudinal length substantially equal to the length of the laser element 20 along the resonator direction. Since the top view shape of the laser element 20 is, for example, a rectangular shape elongated in the cavity direction, such a shape is suitable for suppressing an increase in the area of the submount 21 .

(Relay member a, relay member b)
In this embodiment, as shown in FIGS. 1A and 2A, the relay member 30 is connected to the lead terminal 14 by the wire 40. As shown in FIG. Here, in top view, the relay member 30 arranged in the leftmost row is the relay member 30a, and the relay member 30 arranged in the rightmost row is the relay member 30b. FIG. 1C is an enlarged view of the periphery of the relay member a in FIG. 1A. FIG. 2B is an enlarged view of the periphery of the relay member a in FIG. 2A. As shown in FIGS. 1C and 2B, a first wire 41 that connects the laser element 20a and the relay member 30a is connected to the relay member 30a in the leftmost row. Further, a second wire 42 that connects the lead terminal 14 and the relay member 30a to which the first wire 41 is connected is connected to the relay member 30a. On the other hand, as shown in FIG. 1A, the first wire 41 and the second wire 42 are not connected to the relay member 30b in the rightmost row. That is, since the relay member 30b is connected to the submount 21 by the wire 40, the first wire 41 and the second wire 42 are not connected. As shown in FIG. 1C, when one laser element 20 is arranged on one submount 21, the laser element 20 is arranged on one side (for example, the left side) of the upper surface of the submount 21, and the other side ( For example, the area on the right side) can be a wire bonding area. As a result, the relay member 30a and the relay member 30b are arranged in the laser device 100. As shown in FIG.

In this embodiment, as shown in FIGS. 1C and 2B, the laser element 20a is connected to the relay member 30a by the first wire 41. As shown in FIG. Also, the lead terminal 14 is connected to the relay member 30a by the second wire 42 . The second wire 42 that connects the lead terminal 14 and the relay member 30a, which tend to reach relatively high temperatures, is closer than the first wire 41 that connects the laser element 20a and the relay member 30a, which is less likely to reach a high temperature than the lead terminal 14. is also short. As a result, the fusing current value of the second wire 42 can be increased, so that the possibility of the laser device 100 becoming open can be reduced. As shown in FIG. 2B, in order to make the second wire 42 shorter than the first wire 41, the shortest distance from the relay member 30a to the lead terminal 14 should be larger than the shortest distance from the relay member 30a to the laser element 20a. It is preferable to dispose the relay member 30a so that The shortest distance between the relay member 30a and the laser element 20a can be about 0.1 to 4 mm. The shortest distance between the relay member 30a and the lead terminal 14 can be about 0.1 to 3.5 mm.

As shown in FIG. 1C, when viewed from above, the extending direction of the first wire 41 is preferably substantially parallel to the extending direction of the lead terminal 14, and the extending direction of the second wire 42 is preferably the extending direction of the lead terminal 14. is preferably substantially orthogonal to the In other words, the laser element 20a and the relay member 30a are preferably connected by the first wire 41 extending substantially parallel to the extension direction of the lead terminal 14 . Moreover, it is preferable that the lead terminal 14 and the relay member 30a are connected by a second wire 42 extending in a direction substantially orthogonal to the extension direction of the lead terminal 14 . As a result, the second wire 42 can be made relatively short, and the second wire 42 can be easily connected to the lead terminal 14 . That is, the area of the lead terminal 14 to which the second wire 42 is connected and the area of the relay member 30a to which the second wire 42 is connected can be arranged on a straight line substantially orthogonal to the extending direction of the lead terminal 14. Therefore, it is possible to make the second wire 42 relatively short and to easily connect the second wire 42 to the lead terminal 14 . Note that "substantially parallel" may include not only the case of being strictly parallel, but also the case of deviation from parallel of 20° or less (typically 10° or less). The same is true for substantially orthogonal. The second wire 42 can be connected to the outer edge of the relay member 30a closest to the lead terminal 14 side. This allows the second wire 42 to be relatively short.

As shown in FIG. 1C, the relay member 30a is preferably arranged on the side of the lead terminal 14 when viewed from above. In addition, the side of the lead terminal 14 refers to a direction substantially perpendicular to the extending direction of the lead terminal 14 . As a result, the extending direction of the second wire 42 can be set substantially perpendicular to the extending direction of the lead terminal 14 when viewed from above. Also, the extending direction of the first wire 41 can be set substantially parallel to the extending direction of the lead terminal 14 . In this case, the laser element 20 is preferably arranged such that its cavity direction is substantially perpendicular to the extending direction of the lead terminals 14 . Thereby, a plurality of first wires 41 can be connected along the resonator direction. Also, if the relay member 30a is arranged at a position overlapping the lead terminal 14 in a top view, the area of the upper surface of the relay member 30a to which the wire can be connected is reduced, so that the lead terminal 14 and the relay member 30a may not overlap. preferable. The shortest distance between the lead terminal 14 and the relay member 30a when viewed from above can be about 0.1 to 3.5 mm.

It is preferable that the lead terminal 14 is positioned away from the laser element 20a so as not to block the light from the laser element 20a. Therefore, it is preferable to arrange the relay member 30a near the tip of the lead terminal 14 when viewed from above. As a result, the extending direction of the second wires 42 can be made substantially orthogonal to the extending direction of the lead terminals 14, and an increase in the length of the first wires 41 can be suppressed. Since the first wire 41 becomes longer as the distance from the relay member 30a to the laser element 20a increases, the distance from the relay member 30a to the laser element 20a in top view can be set to about 0.1 to 4 mm. In addition, when viewed from the top, the outer edge of the relay member 30a closest to the laser element 20a is arranged on the side of the inner end of the lead terminal 14, or at a position with a deviation of 2.0 mm or less from that position. be able to.

When viewed from above, the relay member 30a preferably has a rectangular shape having a longitudinal direction and a lateral direction. It is preferable that the extending direction of the first wire 41 is substantially parallel to the longitudinal direction of the relay member 30a, and the extending direction of the second wire 42 is substantially parallel to the lateral direction of the relay member 30a. This makes it difficult for the first wire 41 and the second wire 42 to come into contact with each other while reducing the size of the relay member 30a. That is, on the upper surface of the relay member 30a, the position to which the first wire 41 is connected and the position to which the second wire 42 is connected are arranged along the longitudinal direction of the relay member 30a. and the position where the second wire 42 is connected are arranged along the lateral direction of the relay member a. difficult. In addition, by forming the relay member 30a into such a shape, a part of the region of the relay member 30a to which the wire 40 is not connected can be omitted, so that the relay member 30a can be made smaller.

(wire)
The length of the second wire 42 is preferably 45% to 90% of the length of the first wire 41 . This makes it easier to connect the lead terminal 14 and the relay member a with the second wire 42 while making it difficult to melt the second wire 42 .

Although the laser element 20 a and the relay member 30 a can be connected with one first wire 41 , it is preferable to connect them with a plurality of first wires 41 . Accordingly, even if some of the plurality of first wires 41 are fused, the first wires 41 that are not fused can continue to electrically connect the laser element 20a and the relay member 30a. 100 can be reduced. Each of the plurality of first wires 41 preferably has substantially the same length. Here, "substantially the same length" means that the length difference between the first wires 41 is within 0.1 mm. Thereby, the calorific value of the plurality of first wires 41 can be substantially the same.

As shown in FIG. 1C, the plurality of first wires 41 are preferably connected to the laser element 20 at approximately equal intervals along the cavity length direction of the laser element 20 when viewed from above. As a result, the heat from the laser element 20 can be easily transferred to the first wire 41 substantially evenly. The interval between the first wires 41 can be 0.1 to 0.4 mm.

Gold, copper, aluminum, or the like can be used as the first wire 41 . The length of the first wire 41 is preferably 1 mm to 4 mm. Thereby, the first wire 41 can be stably and easily connected. In addition, the fusing current value can be easily set to 3 A or more. The diameter of the first wire 41 is preferably 45 μm to 80 μm. This range is suitable for connecting a high power laser device 20 .

Although the lead terminal 14 and the relay member 30a can be connected by one second wire 42, it is preferable to connect them by a plurality of second wires 42. FIG. Accordingly, even if some of the plurality of second wires 42 are fused, the second wires 42 that are not fused can continue to electrically connect the lead terminal 14 and the relay member 30a. 100 can be reduced. Each of the plurality of second wires 42 preferably has substantially the same length. Here, "substantially the same length" means that the length difference between the second wires 42 is within 0.1 mm. Thereby, the calorific value of the plurality of second wires 42 can be substantially the same.

Gold, copper, aluminum, or the like can be used as the second wire 42 . The length of the second wire 42 is preferably 0.5 mm to 3.5 mm. Thereby, the second wire 42 can be stably connected easily. In addition, the fusing current value can be easily set to 3 A or more. The diameter of the second wire 42 is preferably 45 μm to 80 μm. This range is suitable for connecting a high power laser device 20 .

(Lid body)
In this embodiment, as shown in FIG. 3, the lid 50 is fixed to the upper surface of the frame 13 so as to close the opening of the frame 13 . The lid 50 has a support portion 50a and a translucent portion 50b provided on the support portion 50a. For example, iron, a nickel-iron alloy, or the like can be used as the support portion 50a. This makes it easier to weld the lid 50 to the frame 13 .

[Example]
This embodiment will be described with reference to FIGS. 1A to 2B.

In this example, as shown in FIGS. 1A and 2A, a package 10 having a substrate 11 provided with eight through holes and eight lead terminals 14 inserted into the eight through holes was used. Base 11 has base 12 and frame 13 fixed to the upper surface of base 12 . Of the four side walls constituting frame 13, two side walls facing each other in the longitudinal direction of frame 13 are provided with four through holes each, and lead terminals 14 are inserted into the respective through holes. The frame 13 has a main body portion 13a and a plate-like portion 13b having a greater thickness than the main body portion 13a. Copper was used as the base 12 . Iron was used as the frame 13 . The substrate 11 had a long side length of 4.8 cm and a short side length of 2.9 cm when viewed from above. As the lead terminal 14, Kovar having a length of 11 mm and a diameter of 600 μm was used. The lead terminal 14 was fixed to the base 11 via glass, which is an insulating member. The contact area between the lead terminal 14 and the insulating member was 15% of the surface area of the lead terminal 14 .

As shown in FIGS. 1A and 2A, 20 laser elements 20 are arranged on the upper surface of the base 12 inside the frame 13 . The laser elements 20 are arranged in a matrix of 5 columns and 4 rows. Among the laser elements 20, the laser element 20 arranged in the left row in top view is the laser element 20a. As the laser element 20, a GaN-based semiconductor laser element having an oscillation wavelength of 455 nm was used. As shown in FIG. 1B, the laser element 20 was junction-down mounted on the upper surface of the base 12 via a submount 21 made of AlN. The thickness of the submount 21 was set to 0.3 mm. The submount 21 had a long side length of 1.5 mm and a short side length of 1.2 mm. The output of one laser element was 4.8W. The laser elements 20 arranged in each row were connected in series, and a voltage of 21V was applied to the laser elements 20 in each row. The resonator direction of the laser element 20 is substantially orthogonal to the extending direction of the lead terminals 14, and the resonator direction of the laser element 20 and the long side of the submount 21 are substantially parallel. A reflecting member 22 made of glass was arranged on the side facing each laser element 20 to reflect the laser light upward.

As shown in FIGS. 1A and 2A, eight relay members 30 made of AlN were arranged on the upper surface of the base portion 12 inside the frame 13 . The relay member 30 was arranged adjacent to the side wall into which the lead terminal 14 was inserted. In other words, the relay members 30 are arranged at both ends of each row in which the laser elements 20 are arranged. The relay member 30 is arranged apart from the submount 21 . Among the relay members 30, the relay member 30 arranged in the left row in top view is the relay member 30a. The thickness of the relay member 30a was set to 0.3 mm. The length of the long side of the relay member 30a was set to 1.1 mm, and the length of the short side was set to 0.9 mm. As shown in FIGS. 1C and 2B, the relay member 30a is arranged such that its longitudinal direction is substantially parallel to the extending direction of the lead terminal 14. As shown in FIG. The relay member 30 a is arranged near the tip of the lead terminal 14 on the side of the lead terminal 14 . The shortest distance between the relay member 30a and the laser element was set to 1.5 mm. The shortest distance between the relay member 30a and the lead terminal 14 was set to 0.6 mm. The shortest distance between the relay member 30a and the laser element a in top view was set to 1.5 mm. The shortest distance between the relay member 30a and the lead terminal 14 in top view was set to 0.8 mm.

As shown in FIGS. 1C and 2B, one laser element 20a and one relay member a were connected by four first wires 41 made of gold. The first wires 41 are connected at approximately equal intervals along the cavity length direction of the laser element 20a on the upper surface of the laser element 20a when viewed from above. The length of each first wire 41 was set to 1.9 mm. The diameter of the first wire 41 was set to 60 μm. The extending direction of the first wire 41 was substantially parallel to the extending direction of the lead terminal 14 when viewed from above.

As shown in FIGS. 1C and 2B, one lead terminal 14 and one relay member 30a were connected by three second wires 42 made of gold. The second wire 42 was connected to the outer edge of the lead terminal 14 side on the upper surface of the relay member a. The length of each second wire 42 was set to 1.0 mm. The diameter of the second wire 42 was set to 60 μm. The extension direction of the second wire 42 was set to be substantially perpendicular to the extension direction of the lead terminal 14 when viewed from above.

Here, in this example, the fusing current values of the first wire 41 and the second wire 42 were measured. When measuring the fusing current value of the first wires 41, three of the four first wires 41 are removed to leave only one first wire 41 so that the first wires 41 can be fused relatively easily. rice field. Also, when measuring the fusing current value of the second wire 42, two of the three second wires 42 are removed and only one second wire 42 is measured so that the second wire 42 can be fused relatively easily. left. As a result, the fusing current value of the first wire 41 was 5.9A, and the fusing current value of the second wire 42 was 6.5A. That is, in the package 10 of the present embodiment, although heat is more likely to accumulate in the lead terminals 14 than in the laser element 20, the fusing current value of the second wires 42 connecting the lead terminals 14 and the relay member 30a is reduced. was larger than the fusing current value of the first wire 41 connecting the laser element 20a and the relay member 30a. It is considered that this is because the length of the second wire 42 is made shorter than the length of the first wire 41 . Therefore, in this embodiment, the fusing current value of the second wire 42 can be increased, and the laser device 100 in which the second wire 42 is less likely to be fused can be obtained.

For comparison with this example, a comparative example was produced in which the length of the first wire 41 was 1.9 mm and the length of the second wire 42 was 1.9 mm. Other than that, it is the same as the present embodiment. In the comparative example, as a result of measuring the fusing current values of the first wire 41 and the second wire 42 in the same manner as in the present embodiment, the fusing current value of the first wire 41 was 5.9 A, and the fusing current value of the second wire 42 was 5.9 A. was 5.5A. This is presumably because, in the comparative example, heat is more likely to accumulate in the lead terminal 14 than in the laser element 20, so that the fusing current value of the second wire 42 has decreased. By making the second wire 42 shorter than the first wire 41 in this manner, the fusing current value of the second wire 42 can be increased, so that the laser apparatus 100 in which the second wire 42 is less likely to be fusing can be obtained. I found out.

REFERENCE SIGNS LIST 100 laser device 10 package 11 base 12 base 13 frame 13a main body 13b plate-shaped portion 14 lead terminal 20 laser element 20a laser element 20b laser element 21 submount 22 reflection member 30 relay member 30a relay member 30b relay member 40 wire 41 1 wire 42 2nd wire 50 lid 50a supporting portion 50b translucent portion

Claims (11)

a base;
a frame fixed to the upper surface of the base and provided with two or more through holes;
two or more lead terminals inserted into the two or more through-holes;
two or more laser elements disposed on the top surface of the base;
a conductive relay member disposed on the upper surface of the base portion away from the two or more lead terminals;
a first wire connecting one of the two or more laser elements and the relay member;
a second wire connecting one of the two or more lead terminals and the relay member;
The extending direction of the first wire is substantially parallel to the extending direction of the lead terminal,
A laser device, wherein the extending direction of the second wire is substantially orthogonal to the extending direction of the lead terminal. a base;
a frame fixed to the upper surface of the base and provided with two or more through holes;
two or more lead terminals inserted into the two or more through-holes;
two or more laser elements disposed on the top surface of the base;
a conductive relay member disposed on the upper surface of the base portion away from the two or more lead terminals;
a first wire connecting one of the two or more laser elements and the relay member;
a second wire connecting one of the two or more lead terminals and the relay member;
The laser device according to claim 1, wherein the relay member is arranged on the side of the lead terminal at a position displaced from the lead terminal in a direction perpendicular to the extending direction of the lead terminal when viewed from above. 3. The laser device according to claim 1, wherein said laser elements are arranged in a matrix. a plurality of first wires connecting the laser element and the relay member;
4. The laser device according to claim 1, wherein a plurality of said second wires connect said lead terminal and said relay member. 5. The laser device according to claim 4, wherein each of said plurality of first wires has substantially the same length. 6. The laser device according to claim 4, wherein the plurality of first wires are connected to the laser element at substantially equal intervals along the cavity length direction of the laser element when viewed from above. . 7. The laser device according to any one of claims 4 to 6, wherein each of the plurality of second wires has substantially the same length. 8. The laser device according to claim 1, wherein a shortest distance between one of said two or more lead terminals and said relay member is 0.1 to 3.5 mm. The laser element is provided on the upper surface of the base via a submount,
9. The laser device according to any one of claims 1 to 8, wherein the submount and the relay member are separated from each other. 10. The laser device according to claim 9, wherein the material and dimensions of said submount are substantially the same as the material and dimensions of said relay member. the relay member is a first relay member,
a conductive second relay member disposed on the upper surface of the base portion away from the two or more lead terminals;
a third wire connecting another one of the two or more laser elements and the second relay member;
11. The laser device according to claim 1, further comprising a fourth wire connecting another one of said two or more lead terminals and said second relay member.

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