KR20200104182A - Stem unit and semiconductor device raser diode package - Google Patents

Abstract

Disclosed are a stem unit and a semiconductor laser diode package. In the stem unit including a clad in which a plurality of class holes are formed and a heat sink bonded to an upper surface of the clad and having an optical element fixed thereto, the clad may include an upper layer formed of copper (Cu) and having a heat sink fixed to an upper surface thereof, a lower layer formed of copper (Cu); and an intermediate layer located between the lower layer and the upper layer and formed of iron (Fe).

Description

Stem unit and semiconductor laser diode package {STEM UNIT AND SEMICONDUCTOR DEVICE RASER DIODE PACKAGE}

The present invention relates to a stem unit and a semiconductor laser diode package, and more particularly, to a stem unit in which a laser diode is mounted and a semiconductor laser diode package for oscillating a laser beam through a laser diode mounted on the stem unit.

In general, since a laser beam oscillated from a laser diode has a narrow frequency width and high directivity, it is applied in various fields such as optical communication, multiple communication, space communication, and the like.

In modern times, as the demand for telecommunication services increases, optical disks that are one of the main application fields of laser diodes along with optical communication networks, namely, Compact Disk Player and Compact Disk Reading/Writing System. In the device, a laser diode having excellent characteristics that can oscillate at a low current and operate for a long time is required.

Such a laser diode is generally composed of a semiconductor laser diode package and fixed to a PCB or the like. The semiconductor laser diode package consists of an optical element, a stem unit that fixes the optical element, a terminal pin and a ground pin for electrically connecting the PCB and the optical element.

Republic of Korea Patent Publication No. 10-1121065, in order to realize various shapes of the base member and heat sink by separately manufacturing the base member forming the stem and the heat sink, "As a stem unit on which an optical element is mounted, a base made of a metal plate A member; A heat sink member manufactured separately from the base member and bonded to an upper surface of the base member to which the optical element is fixed; and a bonding member for bonding the base member and the heat sink, wherein the heat sink A mounting portion on which the optical element is mounted and an extension portion extending from both sides of the mounting portion and bent to surround the optical element, and the bonding member is made of a material having a lower melting point than that of the base member and the heat sink, and the base is used as a brazing method. A stem unit for joining a member and a heat sink is disclosed.

The problem to be solved by the present invention is to provide a stem unit and a semiconductor laser diode package that can be manufactured at low cost while improving thermal conductivity and hermetic bonding.

Another problem to be solved by the present invention is to provide a stem unit and a semiconductor laser diode package with improved bonding strength of the stem.

In order to achieve the problem to be solved, the stem unit according to the present invention includes a clad having a plurality of cras holes formed thereon, and a heat sink bonded to an upper surface of the clad to fix an optical element, The clad is formed of copper (Cu), the upper layer to which the heat sink is fixed to the upper surface; A lower layer formed of copper (Cu); And an intermediate layer positioned between the lower layer and the upper layer and formed of iron (Fe).

The clad may further include a ring layer positioned on the upper layer and formed in a ring shape to surround the plurality of cradle holes and the heat sink. The ring layer may be formed of iron (Fe).

As the heat sink or the ring layer, an alloy of silver (Ag) and copper (Cu) may be used and may be bonded to the upper layer by a brazing method.

A region to which the heat sink is attached may occupy a cross-sectional area of at least half of the upper surface of the upper layer in a region located inside the ring layer.

The heat sink may be formed of copper (Cu).

In order to achieve another object to be solved above, a semiconductor laser diode package according to the present invention includes a stem unit according to the present invention; One or more optical elements fixed to the stem unit; One or more terminal pins attached to one of a plurality of cras holes of the stem unit; And a ground pin attached to the other one of the plurality of cras holes of the stem unit.

According to the stem unit and the semiconductor laser diode package according to the present invention, the clad is composed of an upper layer formed of copper (Cu), an intermediate layer formed of iron (Fe), and a lower layer formed of copper, so that the heat of the optical device through the upper layer having high thermal conductivity It is excellent in heat dissipation by transferring the heat transferred through the lower layer with high thermal conductivity to the outside, and the volume change of the upper and lower layers due to heat is canceled due to the intermediate layer with a low heat sealing coefficient, thereby improving the hermetic bonding, Since the intermediate layer is formed of low-cost iron, it can be manufactured at a low cost, and by providing a golden ratio of the upper layer, the intermediate layer, and the lower layer, there is an effect of improving the bonding strength of the stem.

1 is an exploded perspective view of a preferred embodiment of a semiconductor laser diode package according to the present invention.
2 is a perspective view of a preferred embodiment of a semiconductor laser diode package according to the present invention.
3 is a vertical cross-sectional view of a preferred embodiment of a semiconductor laser diode package according to the present invention.
4 is a horizontal sectional view of a preferred embodiment of a semiconductor laser diode package according to the present invention.
5 is a vertical cross-sectional view of Comparative Example 1.
6 is a vertical cross-sectional view of Comparative Example 2.
7 is a vertical cross-sectional view of Comparative Example 3.

Hereinafter, a stem unit and a semiconductor laser diode package according to the present invention will be described in detail with reference to the accompanying drawings. At this time, the configuration and operation of the present invention shown in the drawings and described by it are described as at least one embodiment, by which the technical idea of the present invention and its core configuration and operation are not limited.

The terms used in the present invention have been selected as currently widely used general terms as possible while considering functions in the present invention, but this may vary according to the intention or custom of a person skilled in the art or the emergence of new technologies. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning of the terms will be described in detail in the description of the corresponding invention. Therefore, it is to be noted that the terms used in the present invention should be defined based on the meaning of the term and the overall contents of the present invention, not a simple name of the term.

1 is an exploded perspective view of a preferred embodiment of a semiconductor laser diode package according to the present invention, Figure 2 is a perspective view of a preferred embodiment of the semiconductor laser diode package according to the present invention, and Figure 3 is a semiconductor laser according to the present invention A vertical cross-sectional view of a preferred embodiment of the diode package, and FIG. 4 is a horizontal cross-sectional view of a preferred embodiment of a semiconductor laser diode package according to the present invention.

1 to 4, the semiconductor laser diode package 10 according to the present invention may include an optical device 20, a stem unit 30, a terminal pin 300, and a ground pin 400.

The optical element 20 is a light source that irradiates a laser beam. The optical device 20 may irradiate a laser beam having the same phase in the same direction. The optical device 20 may be implemented as a laser diode. The semiconductor laser diode package 10 may include one or more optical devices 20.

The stem unit 30 has an optical element 20 attached thereto, and emits high heat generated when the attached optical element 20 is operated. The stem unit 30 includes a clad 100 in which a plurality of cradle holes 101 and 103 are formed, and a heat sink 200 bonded to the upper surface of the clad 100 and fixed to the optical element 20. I can.

The clad 100 is made of metal, and the heat sink 200, the terminal pin 300, and the ground pin 400 are combined. The clad 100 may be implemented in a three-dimensional shape such as a cylindrical shape, a semi-cylindrical shape, and a polygonal cylindrical shape, and may be implemented as a plate material such as a plate shape, an oval shape, and a composite shape.

The clad 100 may be formed by penetrating one or more cross holes 101 and 103 to which the terminal pins 300 are coupled up and down, and a photodiode for sensing the laser beam irradiated by the optical device 20 is mounted. The seating groove 105 may be formed. A photodiode may be mounted in the mounting groove 105.

The clad 100 may include a lower layer 110, an intermediate layer 120, an upper layer 130, and a ring layer 140. The lower layer 110 is located under the intermediate layer 120 and may be formed of copper (Cu). The intermediate layer 120 is positioned between the lower layer 110 and the upper layer 130 and may be formed of iron (Fe). The upper layer 130 is formed on the intermediate layer 120 and may be formed of copper (Cu). The heat sink 200 may be fixed to the upper surface of the upper layer 130 and a seating groove 105 may be formed. In the present invention, since the upper layer 130 is formed of copper having high thermal conductivity, it receives heat from the optical device 20 through the heat sink 200 and transfers the heat received through the lower layer 110 formed of copper to the outside. It has excellent thermal conductivity and heat dissipation by transferring, and since the intermediate layer 120 is formed of iron having a low heat seal coefficient, the volume change of the upper layer 130 and the lower layer 110 due to heat is canceled to improve airtight bonding, while the intermediate layer ( 120) As it is formed of iron with a low unit price, there is an effect that it can be manufactured at a low cost.

Preferably, the lower layer 110, the intermediate layer 120, and the upper layer 130 may have a thickness ratio of 1:2:1. Accordingly, the clad 100 has an optimal effect of reducing production cost while maintaining excellent heat release and airtight bonding.

The ring layer 140 is positioned on the upper layer 130 and is formed in a ring shape to surround a plurality of cradle holes 101 and 103, a seating groove 105, and a heat sink 200. The ring layer 140 may be bonded to the upper layer 130 by a brazing method by using an alloy of silver (Ag) and copper (Cu), and may be formed integrally with the upper layer 130. The ring layer 140 may be formed of iron (Fe). Accordingly, the ring layer 140 is formed of iron having a low heat seal coefficient, thereby canceling a volume change of the upper layer 130 made of copper (Cu) having a high heat seal coefficient, thereby improving the hermetic bonding.

The terminal pin 300 is a means for supplying power to the optical device 20 and the photodiode, and may be fixed to protrude from the upper and lower portions of the clad 100 through the clad hole 101 formed in the clad 100. . At this time, between the terminal pin 300 and the clad 100 may be insulated by an insulator 190. Accordingly, one side of the terminal pin 300 may be connected to the optical device 20, the photodiode, and the wire 21, and the other side may be connected to the outside. Here, a substrate such as a PCB may be located outside the substrate, and the other side of the terminal pin 300 may be connected to the substrate. In addition, the terminal pin 310 may pass through the cras hole 103 and be fixed to protrude upward and downward of the clad 100.

The ground pin 400 may be bonded to the lower surface of the clad 100 to be physically and electrically connected. At this time, the ground pin 400 may be fixed by simple welding, or may be fixed to the clad 100 via the welding material 401. The ground pin 400 may ground the stem unit 30.

The heat sink 200 has an optical element 20 mounted thereon and has a function and function of directly dissipating high heat generated from the optical element 20, and may be manufactured integrally with the clad 100 or separately manufactured. . In addition, the heat sink 200 may be manufactured to protrude from the upper surface of the clad 100. In some embodiments, the heat sink 200 may be bonded to the upper layer 130 by a brazing method by using an alloy of silver (Ag) and copper (Cu).

Preferably, the heat sink 200 may be manufactured such that a region to which the heat sink 200 is attached occupies half or more of a cross-sectional area of an upper surface of the upper layer 130 located inside the ring layer 140. Accordingly, in the present invention, thermal conductivity may be improved.

Preferably, the heat sink 200 is attached to occupy an area including the center of the clad 30, and a straight line passing through the midpoint of the clad hole 101 and the midpoint of the clad hole 103 and the center of the clad 30 The distance between the ring layers 140 may be smaller than half the length of the inner radius. Accordingly, the cross-sectional area of the heat sink 200 attached to the clad 30 may be increased, and heat dissipation of the clad 30 may be improved.

Preferably, the heat sink 200 may be formed of copper (Cu). Accordingly, in the present invention, the heat radiated by the optical device 20 is transferred to the clad 100 through copper having excellent thermal conductivity, so that the heat conductivity and heat dissipation property are excellent, and the heat sink 200 and the upper layer 130 Since it is made of such a material, the thermal conductivity and bonding property between the clad 100 and the heat sink 200 are more excellent.

5 is a vertical cross-sectional view of Comparative Example 1, FIG. 6 is a vertical cross-sectional view of Comparative Example 2, and FIG. 7 is a vertical cross-sectional view of Comparative Example 3.

5 to 7, an experiment was conducted to compare the characteristics of the examples of the present invention and the comparative examples, and the results are shown in Table 1 below. In the Examples and Comparative Examples, the thickness of the clad and the heat sink were the same, and the longest cross-sectional area of the clad was the same, except for Comparative Example 3, the clad and heat sink were made of silver (Ag) and copper (Cu) alloys. And joined by a brazing method. However, the cross-sectional area of the heat sink of Example 1 was made to occupy more than half of the inner area of the ring layer, and the cross-sectional area of the heat sink of Example 2 was made smaller than half of the inner area of the ring layer, and the heat sinks of Comparative Examples 1 to 3 The cross-sectional area of was prepared equal to the cross-sectional area of Example 2. In addition, the structural shapes of Comparative Examples 1 to 3 are the same as in FIGS. 5 to 7 respectively.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Heat sink material Copper (Cu) Copper (Cu) Copper (Cu) Copper (Cu) Copper (Cu) Clad material Copper (Cu)
Iron (Fe)
Copper (Cu) Copper (Cu)
Iron (Fe)
Copper (Cu) Iron (Fe) Copper (Cu) Copper (Cu) join AgCu Brazing AgCu Brazing AgCu Brazing AgCu Brazing Single manufacturing Ring layer material Iron (Fe) Iron (Fe) Iron (Fe) Iron (Fe) Iron (Fe) Ring layer bonding AgCu Brazing AgCu Brazing AgCu Brazing AgCu Brazing AgCu Brazing Heat release 5 4 2 4 5 Hermetic bonding 4 4 4 2 2 cost 4 4 4 2 One Comprehensive evaluation 4.33 4 3.33 2.66 2.66

(5: very good, 4: excellent, 3: moderate, 2: bad, 1: very bad)

As can be seen from the experimental results of Table 1, it can be seen that Examples 1 and 2 according to the present invention are superior to the conventional Comparative Examples 1 to 3 in the comprehensive evaluation because heat release properties, airtight bonding and cost are inexpensive. In particular, it can be seen that Example 1 exhibits heat release property equivalent to Comparative Example 3 made of integral copper.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific preferred embodiments described above, and without departing from the gist of the present invention claimed in the claims, in the technical field to which the present invention pertains. Anyone of ordinary skill in the art can implement various modifications, as well as such modifications will be within the scope of the claims.

Semiconductor Laser Diode Package(10) Optical Device(20)
Stem unit (30) Clad (100)
Heat sink (200) terminal pin (300)
Ground pin (400)

Claims (7)

In the stem unit comprising a clad (clad) in which a plurality of crasholes are formed, a heat sink bonded to an upper surface of the clad to fix an optical element,
The clad,
An upper layer formed of copper (Cu) and on which the heat sink is fixed;
A lower layer formed of copper (Cu); And
It is located between the lower layer and the upper layer, the stem unit, characterized in that it comprises an intermediate layer formed of iron (Fe). The method of claim 1,
The clad,
And a ring layer disposed on the upper layer and formed in a ring shape to surround the plurality of cras holes and the heat sink. The method of claim 2,
The ring layer,
Stem unit, characterized in that formed of iron (Fe). The method of claim 2,
The heat sink or the ring layer,
A stem unit, characterized in that an alloy of silver (Ag) and copper (Cu) is used and bonded to the upper layer by a brazing method. The method of claim 2,
A stem unit, characterized in that at least half of the area to which the heat sink is attached occupies a cross-sectional area of the upper surface of the upper layer in a region located inside the ring layer. The method of claim 1,
The heat sink is a stem unit, characterized in that formed of copper (Cu). A stem unit according to any one of claims 1 to 6;
One or more optical elements fixed to the stem unit;
One or more terminal pins attached to one of a plurality of cras holes of the stem unit; And
A semiconductor laser diode package comprising a ground pin attached to the other of the plurality of cras holes of the stem unit.

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