TO packaging structure for improving temperature difference between front cavity surface and rear cavity surface of FP cavity laser and application of TO packaging structure

Abstract

The invention provides a TO packaging structure for improving the temperature difference between the front cavity surface and the rear cavity surface of an FP cavity laser and application, and belongs to the technical field of semiconductor lasers. The TO packaging structure comprises a pedestal main body on which a base station of a laser and a chip are arranged, and the front side of the pedestal main body is flush with the chip; the extension part extends out from the front side of the base body, the bottom of the extension part is flush with the bottom of the base body, the top of the extension part is not higher than the top of the base body, and the extension length of the top of the extension part is not larger than the extension distance of the bottom of the extension part; the radial section of the extending part on the plane perpendicular to the extending direction of the extending part is a rectangle, a right triangle or a right trapezoid. According to the TO packaging structure provided by the invention, the temperature difference existing in the active area of the laser chip in the ridge direction can be remarkably reduced, the stability and consistency of the output wavelength of the laser are improved, and meanwhile, the front cavity surface is kept flush with the heat sink without influencing the quality of an output light beam.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor lasers, and in particular relates to a TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of an FP cavity laser and an application thereof. Background Art

[0002] With the continuous expansion of semiconductor laser application fields, the requirements for semiconductor laser performance are getting higher and higher. Packaging technology not only provides structural support and protection for lasers, but also serves as the main heat dissipation channel for lasers. The packaging structure has become one of the key factors affecting device performance and reliability.

[0003] The junction temperature and distribution of semiconductor lasers are the main factors affecting threshold current, output power, wavelength and reliability. For commonly used FP cavity lasers, in addition to the temperature inhomogeneity caused by current injection and mode distribution perpendicular to the ridge direction, there is also a temperature difference between the front and rear cavity surfaces caused by the asymmetric heat dissipation of the TO package along the ridge direction. The former is more obvious in high-power semiconductor lasers, while the latter is common in FP cavity lasers of various powers. How to optimize the heat dissipation performance of the laser, especially the temperature distribution inhomogeneity, starting from the packaging structure is the key to improving the output performance and reliability of the laser.

[0004] When high-power FP cavity lasers are working, the junction temperature distribution is significantly non-uniform, which will cause laser wavelength drift, beam and spectrum quality to deteriorate, seriously affecting the high-precision application of lasers, resulting in poor system accuracy and data transmission quality. In addition, the uneven junction temperature distribution will also cause thermal stress inside the laser. Long-term thermal stress and cycles will cause device fatigue and degradation, reducing the long-term reliability of the laser.

[0005] Traditional semiconductor laser packaging forms include: (1) TO (Transistor Outline) packaging, also known as transistor outline packaging. The main forms include window packaging, pigtail packaging with pigtail and connector, and plug-in packaging with connector but no pigtail. (2) COB (Chip On Board) packaging, that is, the laser chip is directly bonded to the substrate through conductive or non-conductive glue, and its electrical connection is achieved through wire bonding. However, since the chip is exposed, it is susceptible to interference and contamination, and has poor reliability. (3) Box packaging, with a large internal space, usually places a semiconductor cooler in the structure as a temperature control module unit to monitor and control the temperature of the LD chip in real time to improve performance stability.

[0006] Different packaging methods have their own advantages and disadvantages. Among them, TO packaging has low cost, stable structure, wide application range, and easy coupling and alignment, and is widely used in FP cavity semiconductor laser packaging. However, due to the influence of the heat dissipation path of the TO packaging structure, the temperature difference problem between the front and rear surfaces of the FP cavity laser has not yet been solved. Summary of the invention

[0007] The present invention is developed to solve the problem of temperature difference between front and rear cavity surfaces of FP cavity lasers, and aims to provide a TO packaging structure and application for improving the temperature difference between front and rear cavity surfaces of FP cavity lasers.

[0008] The present invention provides a TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of an FP cavity laser. The structure has the following characteristics: as a base of the FP cavity laser and used to improve the temperature difference between the front and rear cavity surfaces of the FP cavity laser, the structure comprises: a base body, used for arranging a base and a chip of the FP cavity laser thereon, and the front side of the base body is flush with the chip; and an extension portion, extending from the front side of the base body, the bottom of the extension portion is flush with the bottom of the base body, the top of the extension portion is not higher than the top of the base body, the extension length of the top of the extension portion is not greater than the extension distance of the bottom thereof, and the radial cross section of the extension portion on a plane perpendicular to the extension direction thereof is a rectangle, a right triangle or a right trapezoid.

[0009] In the TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention, it can also have the following characteristics: wherein, when the radial cross-section of the extension portion on a plane perpendicular to its extension direction is a rectangle, the TO packaging structure is a stepped TO tube, the extension length of the extension portion is the width of the rectangle, the height of the extension portion is the height of the rectangle, the extension length of the extension portion is recorded as x1, the height of the extension portion is recorded as x2, the height of the base body is h, x1=0.1mm~1mm, 0.5≤x2 / h≤0.9.

[0010] In the TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention, it can also have the following characteristics: wherein, when the radial cross-section of the extension portion on a plane perpendicular to its extension direction is a right triangle, the TO packaging structure is a trapezoidal TO tube, the extension length of the extension portion and its height correspond to the lengths of the two right-angled sides of the right triangle, and the height of the extension portion is equal to the height of the base body.

[0011] In the TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention, it can also have the following characteristics: wherein, when the radial cross-section of the extension portion on a plane perpendicular to its extension direction is a right-angled trapezoid, the TO packaging structure is an inclined table-top TO tube, and the extension length of the extension portion is the height of the right-angled trapezoid, and the height of the right-angled trapezoid is recorded as x3; the length of the upper base is recorded as x4; the length of the lower base is the same as the height of the base body, both are h, 0.5≤x4 / h<1, x3=0.1mm~1mm.

[0012] The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention may also have the following feature: wherein the TO packaging structure is a heat sink material.

[0013] The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention may also have the following characteristics: wherein the heat sink material may be Cu, Cu-W alloy or the like.

[0014] The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention may also have the following feature: wherein the base body and the extension portion are integrally formed.

[0015] The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention may also have the following characteristics: wherein the FP cavity laser includes a red light FP cavity laser, a blue light FP cavity laser or a green light FP cavity laser.

[0016] The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser provided by the present invention may also have the following characteristics: the base and the TO packaging structure are connected by solder, and the chip and the base are connected by solder.

[0017] The present invention also provides an application of a TO packaging structure in an FP cavity laser, wherein the TO packaging structure is used to significantly improve the temperature difference between the front and rear cavity surfaces of the FP cavity laser.

[0018] Functions and Effects of the Invention

[0019] The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to the present invention comprises: a base body, on which the base and chip of the laser are arranged, and the front side of the base body is flush with the chip; and an extension portion, which extends from the front side of the base body, the bottom of the extension portion is flush with the bottom of the base body, the top of the extension portion is not higher than the top of the base body, the extension length of the top of the extension portion is not greater than the extension distance of its bottom, and the radial cross section of the extension portion on a plane perpendicular to its extension direction is a rectangle, a right triangle or a right trapezoid.

[0020] Therefore, the TO packaging structure of the present invention can significantly reduce the temperature difference in the active area of ​​the laser chip along the ridge direction, improve the stability and consistency of the laser output wavelength, and at the same time, keep the front cavity surface flush with the heat sink without affecting the output beam quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a side view of the TO package structure and the FP cavity laser in Example 1 of the present invention;

[0022] Figure 2 is a top view of the TO packaging structure and the FP cavity laser in Example 1 of the present invention;

[0023] Figure 3 is a side view of the TO packaging structure and the FP cavity laser in Example 2 of the present invention;

[0024] Figure 4 is a top view of the TO packaging structure and the FP cavity laser in Example 2 of the present invention;

[0025] Figure 5 is a side view of the TO packaging structure and the FP cavity laser in Example 3 of the present invention;

[0026] Figure 6 It is a top view of the TO packaging structure and the FP cavity laser in Example 3 of the present invention. DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments and drawings specifically illustrate a TO packaging structure and application of the present invention for improving the temperature difference between the front and rear cavity surfaces of an FP cavity laser.

[0028] <Example 1>

[0029] Figure 1 is a side view of the TO package structure and the FP cavity laser in Example 1 of the present invention; Figure 2 It is a top view of the TO packaging structure and the FP cavity laser in Example 1 of the present invention.

[0030] like Figure 1 and 2 As shown, this embodiment provides a TO packaging structure 10 for improving the temperature difference between the front and rear cavity surfaces of an FP cavity laser, which serves as a base of the FP cavity laser 100 and is used to improve the temperature difference between the front and rear cavity surfaces of the FP cavity laser 100 .

[0031] The FP cavity laser 100 is a red light FP cavity laser, a blue light FP cavity laser or a green light FP cavity laser.

[0032] The TO package structure 10 includes a base body 11 and an extension portion 12 that are integrally formed, and is a stepped TO tube.

[0033] The base body 11 in this embodiment is a rectangular plate structure made of Cu material, and its thickness is h. The top front side of the base body 11 is flush with the front side of the base 20. In this embodiment, the base 20 is set on the base body 11 by solder, the chip 30 is set on the base 20 by solder, and the top front side of the base body 11 is flush with the front sides of the base 20 and the chip 30.

[0034] The extension portion 12 extends from the front side of the base body 11, the bottom of the extension portion 12 is flush with the bottom of the base body 11, and the top of the extension portion 12 does not exceed the top of the base body 11; the extension length of the top of the extension portion 12 is not greater than the extension distance of its bottom, and the radial cross-section of the extension portion 12 on a plane perpendicular to its extension direction is a rectangle.

[0035] The extension length of the extension portion 12 (ie, the width of the rectangle) is denoted as x1, and the height of the extension portion 12 (ie, the height of the rectangle) is denoted as x2, x1=0.1 mm to 1 mm, 0.5≤x2 / h≤0.9.

[0036] <Example 2>

[0037] Figure 3 is a side view of the TO packaging structure and the FP cavity laser in Example 2 of the present invention; Figure 4 It is a top view of the TO packaging structure and the FP cavity laser in Example 2 of the present invention.

[0038] like Figure 3 and 4 As shown, this embodiment provides a TO packaging structure 10' for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser, which serves as a base of the FP cavity laser 100' and is used to improve the temperature difference between the front and rear cavity surfaces of the FP cavity laser 100'.

[0039] The TO packaging structure 10 ′ includes a base body 11 and an extension portion 12 ′ which are integrally formed and are a trapezoidal TO tube.

[0040] The arrangement of the base body 11, the base 20 and the chip 30 in this embodiment is generally similar to that in the first embodiment and will not be repeated. The only difference is that the radial cross section of the extension portion 12' on a plane perpendicular to its extension direction is a right triangle, the extension length and height of the extension portion 12' correspond to the lengths of the two right-angled sides of the right triangle, and the height of the extension portion 12' is equal to the height of the base body 11.

[0041] <Example 3>

[0042] Figure 5is a side view of the TO packaging structure and the FP cavity laser in Example 3 of the present invention; Figure 6 It is a top view of the TO packaging structure and the FP cavity laser in Example 3 of the present invention.

[0043] like Figure 5 and 6 As shown, this embodiment provides a TO packaging structure 10 ″ for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser, which serves as a base of the FP cavity laser 100 ″ and is used to improve the temperature difference between the front and rear cavity surfaces of the FP cavity laser 100 ″.

[0044] The TO packaging structure 10 ″ includes a base body 11 and an extension portion 12 ″ which are integrally formed and are a TO tube with an inclined surface.

[0045] The arrangement of the base body 11, the base 20 and the chip 30 in this embodiment is generally similar to that in the first embodiment and will not be repeated. The only difference is that the extension portion 12" extends from the front side of the base body 11, the bottom of the extension portion 12" is flush with the bottom of the base body 11, and the top of the extension portion 12" does not exceed the top of the base body 11; the extension length of the top of the extension portion 12" is not greater than the extension distance of its bottom, and the radial cross section of the extension portion 12" on a plane perpendicular to its extension direction is a right-angle trapezoid.

[0046] The height of the right trapezoid is recorded as x3; the length of the upper base is recorded as x4; the length of the lower base is the same as the height of the base body 11, both are h, 0.5≤x4 / h<1, x3=0.1mm~1mm.

[0047] Functions and Effects of the Embodiments

[0048] The TO packaging structure of this embodiment does not affect the temperature difference between the ridges of the FP cavity laser, reduces the temperature difference of the laser chip along the ridge direction, improves the temperature uniformity of the active area, and improves the optical performance and output stability of the FP cavity laser.

[0049] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of an FP cavity laser, characterized in that: As a base of a FP cavity laser and used to improve the front and rear cavity surface temperature difference of the FP cavity laser, comprising: A base body, for arranging the base and the chip of the FP cavity laser thereon, and the front side of the base body is flush with the chip; and An extension portion extends from the front side of the base body, the bottom of the extension portion is flush with the bottom of the base body, and the top of the extension portion is not higher than the top of the base body, The extension length of the top of the extension portion is not greater than the extension distance of the bottom thereof, The radial cross section of the extension portion on a plane perpendicular to the extension direction thereof is a rectangle, a right triangle or a right trapezoid.

2. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 1, characterized in that: in, When the radial cross section of the extension portion on a plane perpendicular to the extension direction thereof is rectangular, the TO packaging structure is a stepped TO tube. The extension length of the extension portion is equal to the width of the rectangle, and the height of the extension portion is equal to the height of the rectangle. The extension length of the extension portion is denoted as x1, the height of the extension portion is denoted as x2, and the height of the base body is denoted as h. x1=0.1mm~1mm, 0.5≤x2 / h≤0.

9.

3. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 1, characterized in that: in, When the radial cross section of the extension portion on a plane perpendicular to the extension direction thereof is a right triangle, the TO packaging structure is a trapezoidal TO tube. The extension length and height of the extension portion correspond to the lengths of the two right-angled sides of the right triangle, and the height of the extension portion is equal to the height of the base body.

4. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 1, characterized in that: in, When the radial cross section of the extension portion on a plane perpendicular to its extension direction is a right-angle trapezoid, the TO packaging structure is an inclined table-shaped TO tube. The extension length of the extension portion is equal to the height of the right-angled trapezoid. The height of the right-angled trapezoid is recorded as x3; the length of the upper base is recorded as x4; the length of the lower base is the same as the height of the base body, both are h. 0.5≤x4 / h<1, x3=0.1mm~1mm.

5. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 1, characterized in that: in, The TO packaging structure is a heat sink material.

6. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 5, characterized in that: in, The heat sink material may be Cu, Cu-W alloy or the like.

7. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 1, characterized in that: in, The base body and the extension portion are designed to be integrally formed.

8. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 1, characterized in that: in, The FP cavity laser includes a red light FP cavity laser, a blue light FP cavity laser or a green light FP cavity laser.

9. The TO packaging structure for improving the temperature difference between the front and rear cavity surfaces of the FP cavity laser according to claim 1, characterized in that: in, The base is connected to the TO packaging structure via solder, and the chip is connected to the base via solder.

10. Application of the TO packaging structure according to any one of claims 1 to 9 in a FP cavity laser, in, The TO packaging structure is used to significantly improve the temperature difference between the front and rear cavity surfaces of the FP cavity laser.

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