TWI632751B - Package structure of semiconductor laser - Google Patents

Abstract

A semiconductor laser package structure comprising: a heat sink base; a laser element secured to a surface of the heat sink base; and an optical component. The laser element emits a laser beam. Additionally, the optical element has a reflective curved surface to change a direction of travel of the laser beam and to change a first divergence angle of the laser beam.

Description

Semiconductor laser package structure

This invention relates to a package structure, and more particularly to a package structure for a semiconductor laser.

Please refer to FIG. 1 , which is a package structure of a conventional semiconductor laser. It is disclosed in Taiwan Patent Publication No. TWI568117B.

The semiconductor laser package structure includes a circuit board 410, a laser diode 402, a primary adhesion substrate 404, and an optical component 332. The laser diode 402 is fixed to the sub-adhesive substrate 404. The secondary adhesive substrate 404 and the optical component 332 are fixed to a surface of the circuit board 410. In addition, the laser diode 402 is a semiconductor laser, and the circuit board 410 is a heat sink.

In this package structure, the laser diode 402 emits a laser beam 420 from the front surface and directly illuminates the reflective surface 331 of the optical element 332. The laser beam 420 changes the path of the laser beam 420 via the reflective surface 331 of the optical element 332. In other words, the laser beam 420 output by the laser diode 402 can be reflected by the reflecting surface 331. That is, the optical element 332 in the conventional semiconductor laser package structure can reflect and steer the laser beam of the edge-emitting laser diode 402 to form a surface-emitting laser.

Moreover, in the final packaging process, a silicone (not shown) may be filled on the circuit board 410 to cover all components to protect all components on the circuit board 410.

As is well known, the laser beam 420 output by the laser diode 402 is an elliptical laser beam, and the divergence angle of the laser beam 420 is very large. In general, the vertical divergence angle of the laser beam is greater than the horizontal divergence angle, and the vertical divergence angle is approximately 30 degrees up and down.

In order to effectively control the divergence angle of the laser beam 420. In addition to the conventional semiconductor laser package structure, it is necessary to mount the lens system and use the lens system to change the shape of the laser beam 420. For example, the elliptical laser beam 420 is changed to a circular laser beam.

Obviously, after mounting the lens system outside the conventional semiconductor laser package structure, the volume of the entire laser device will become larger, and the lens system will inevitably increase the manufacturing cost of the laser device.

The main object of the present invention is to provide a semiconductor laser package structure and related components. The present invention contemplates a new optical component. In addition to reflecting and steering the laser beam output from the edge-emitting laser diode, the optical element can also change the shape of the laser beam. That is, the laser device of the present invention can be simplified to completely omit the lens system that changes the laser beam. In this way, the volume of the entire laser device can be greatly reduced, and the manufacturing cost of the laser device can be reduced.

The invention relates to a semiconductor laser package structure, comprising: a heat dissipation base; a laser element fixed to a surface of the heat dissipation base to emit a laser beam; and an optical component having a Reflecting the curved surface to change a direction of travel of the laser beam and changing a first divergence angle of the laser beam.

In order to provide a better understanding of the above and other aspects of the present invention, the following detailed description of the embodiments and the accompanying drawings

Please refer to FIG. 2, which illustrates a first embodiment of the optical component of the present invention. The optical element 532 of the present invention can be etched on the ruthenium substrate to form a curved surface. After the surface is processed, the reflective curved surface 531 of the optical element 532 can be formed, and the optical element 532 can change the shape of the laser beam in addition to changing the direction in which the laser beam travels, and effectively change the divergence of the laser beam. angle.

The material of the optical element 532 of the present invention may be made of gallium arsenide, ceramic, plastic or glass in addition to the germanium substrate. That is, the optical element 532 is fabricated by an etching process of a gallium arsenide substrate, a ceramic substrate, a plastic injection molding, or a glass mold. In addition, in addition to forming a curved surface by an etching process, a polishing process or a cutting process (for example, a numerical control (CNC) cutting process) may be used to form a curved surface. Of course, the present invention can form a reflective layer, such as a dielectric reflective layer or a metal reflective layer, on the curved surface to form a reflective curved surface 531. In this way, the reflectance of the reflective curved surface 531 can be improved.

As shown in Fig. 2, the reflection curved surface 531 is a columnar reflection curved surface. This reflective curved surface 531 can primarily change a divergence angle of the laser beam, such as reducing the vertical divergence angle of the laser beam. In addition, the length d1 of the optical element 532 is between about 200 μm and 1000 μm, and the height d3 is between about 100 μm and 1000 μm. The width d2 can be determined according to actual needs.

Please refer to FIG. 3, which illustrates a second embodiment of the optical component of the present invention. The first embodiment is comparable in size to the second embodiment. Furthermore, the reflective curved surface 541 of the optical element 542 of the second embodiment is an aspherical reflective curved surface 541 compared to the optical element 532 of the first embodiment. For example, an elliptical reflective surface or a parabolic reflective surface. Therefore, the reflective curved surface 541 can simultaneously change the vertical divergence angle and the horizontal divergence angle of the laser beam. For example, the reflective curved surface 541 can simultaneously reduce the vertical divergence angle of the laser beam and reduce the horizontal divergence angle of the laser beam.

Of course, the reflective surface of the optical element can be further modified. As shown in Fig. 4, a third embodiment of the optical element of the present invention. The third embodiment is comparable in size to the first embodiment. The optical element 552 of the third embodiment, whose reflective curved surface 551 can also simultaneously change the vertical divergence angle and the horizontal divergence angle of the laser beam. That is, the reflective curved surface 551 can reduce the vertical divergence angle of the laser beam and increase the horizontal divergence angle of the laser beam.

Of course, the optical elements 532, 542, and 552 described above may be further fabricated into an optical element having a reflection function and a light detecting function. Taking the optical element 532 of the first embodiment as an example, the optical element 532 has a PN junction, and the reflective curved surface 531 can be designed as a reflective layer having a specific reflectivity, such as a dielectric reflective layer. For example, 95% reflectivity, 5% transmittance of the dielectric reflective layer. Therefore, part of the laser beam that has penetrated the dielectric reflective layer enters the PN junction, that is, an induced photocurrent is generated by the photoelectric effect to indicate the energy of the laser beam. The other part of the laser beam is reflected by the dielectric reflective layer.

Please refer to FIG. 5, which illustrates the package structure of the present invention. The package structure includes a circuit board 600, a laser diode 602, a primary adhesion substrate 604, and an optical component 632. The laser diode 602 is fixed to the sub-adhesive substrate 604. In addition, the secondary adhesive substrate 604 and the optical element 632 are fixed to the surface of the circuit board 600. Furthermore, the laser diode 602 and the sub-adhesive substrate 604 form a laser element, and the distance d4 between the laser diode 602 and the optical element 632 is about 10 μm to 500 μm, and the circuit board 600 is a heat dissipation base. seat.

In this package structure, the laser diode 602 emits a laser beam 640 from the front surface and directly illuminates the reflective curved surface 631 of the optical element 632. The laser beam 640 changes the direction of travel of the laser beam 640 via the reflective curved surface 631 of the optical element 632. Furthermore, the laser beam 640 changes the divergence angle of the laser beam 640 via the reflective curved surface 631 of the optical element 632. For example, the reflective curved surface 631 can change the vertical divergence angle from about 30 degrees to 8 degrees.

As can be seen from the above description, the laser beam 640 output from the laser diode 602 can be reflected by the reflective curved surface 631. That is, the optical element 632 in the conventional semiconductor laser package structure can reflect and steer the laser beam of the edge-emitting laser diode 602 to form a surface-emitting laser. At the same time, the shape of the laser beam 640 can also be changed via the reflective curved surface 631, such as a laser beam that is changed from a elliptical laser beam to a circular laser beam.

Moreover, in the final packaging process, a silicone (not shown) may be filled on the circuit board 600 to cover all components to protect all components on the circuit board 600.

In addition, in the package structure of FIG. 4, the laser element includes a laser diode 602 and a sub-adhesive substrate 604. A person skilled in the art can also use the laser diode 602 as a laser element and directly fix the laser diode 602 to the circuit board 600, and the object of the present invention can be achieved.

As apparent from the above description, the present invention has an advantage in that a semiconductor laser package structure and related components are proposed. The present invention contemplates a new optical component. By designing the radius of curvature of each point on the reflective surface in the optical component, the divergence angle of the laser beam can be effectively changed. In other words, the optical element of the present invention can change the shape of the laser beam in addition to reflecting and steering the laser beam output from the edge-emitting type laser diode. That is, the laser device of the present invention can simplify or even completely omit the lens system that changes the laser beam. In this way, the volume of the entire laser device can be greatly reduced, and it has the advantage of being small in size, and can be applied to small electronic devices such as mobile phones.

In conclusion, the present invention has been disclosed in the above embodiments, but it is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

332, 532, 542, 552, 632‧‧‧ optical components

331‧‧‧reflecting surface

402, 602‧‧ ‧ laser diode

404, 604‧‧ ‧ adhesion substrates

410, 600‧‧‧ circuit board

420, 640‧‧ ‧ laser beam

531, 541, 551, 631‧‧‧ reflective surface

Figure 1 is a package structure of a conventional semiconductor laser. Figure 2 is a first embodiment of the optical component of the present invention. Figure 3 is a second embodiment of the optical component of the present invention. Figure 4 is a second embodiment of the optical element of the present invention. Figure 5 is a package structure of the present invention.

Claims (18)

A semiconductor laser package structure comprising: a heat sink base; an optical component having a reflective curved surface; and a laser component fixed to a surface of the heat sink base, wherein the laser component is along a first Transmitting a laser beam in a direction of travel and directly illuminating the reflective surface of the optical element; wherein the reflective curved surface of the optical element changes the laser beam from the first direction of travel to a second direction of travel and changes the Ray A first divergence angle of the beam. The semiconductor laser package structure according to claim 1, wherein the heat dissipation base is a circuit board, and the laser element comprises a laser diode and a primary adhesion substrate, and the laser diode is fixed. The substrate is adhered to the substrate, and the adhesive substrate is fixed to the circuit board. The semiconductor laser package structure of claim 1, wherein the heat dissipation base is a circuit board, and the laser element comprises a laser diode fixed to the circuit board. The semiconductor laser package structure of claim 1, wherein the material of the optical component is a ceramic, a plastic or a glass. The semiconductor laser package structure of claim 4, wherein the reflective surface is formed on the optical component by a polishing process, a cutting process, an injection molding process, or a molding process. The semiconductor laser package structure of claim 1, wherein the reflective surface further comprises a dielectric reflective layer or a metal reflective layer. The semiconductor laser package structure of claim 1, wherein the reflective surface is an aspherical reflective surface. The semiconductor laser package structure of claim 7, wherein the reflective surface is a columnar reflective surface, a parabolic reflective surface or an elliptical reflective surface. The semiconductor laser package structure of claim 8, wherein the columnar reflective surface changes a vertical divergence angle of the laser beam. The semiconductor laser package structure of claim 8, wherein the elliptical reflective surface and the parabolic reflective surface change a vertical divergence angle and a horizontal divergence angle of the laser beam. The semiconductor laser package structure of claim 1, wherein the reflective curved surface reflects the laser beam and changes a second divergence angle of the laser beam. The semiconductor laser package structure of claim 11, wherein the first divergence angle is a vertical divergence angle, and the second divergence angle is a horizontal divergence angle. The semiconductor laser package structure of claim 12, wherein the reflective surface reduces the vertical divergence angle of the laser beam and reduces the horizontal divergence angle of the laser beam. The semiconductor laser package structure of claim 12, wherein the reflective surface reduces the vertical divergence angle of the laser beam and increases the horizontal divergence angle of the laser beam. The semiconductor laser package structure of claim 1, wherein the distance between the laser element and the optical element is between 10 μm and 500 μm. The semiconductor laser package structure of claim 1, wherein the optical element has a height between 100 μm and 1000 μm. The semiconductor laser package structure of claim 1, wherein the optical element has a length between 200 μm and 1000 μm. The semiconductor laser package structure of claim 1, wherein the optical element has a PN junction, and the reflective curved surface has a reflective layer; wherein a first portion of the laser beam passes through the The reflective layer enters the PN junction to generate an induced photocurrent; and a second portion of the laser beam is reflected by the reflective layer.