Laser packaging structure
By preparing bar bars of visible light absorbing material on the top of the heat sink of the semiconductor laser package, the beam quality deterioration caused by cavity surface luminescence is solved, the far-field imaging effect of the laser beam is optimized, and the packaging yield and cost control are improved .
Patent Information
- Application Number
- CN202421119899.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-22
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-05-22
AI Technical Summary
In the existing semiconductor laser package, insufficient optical structure design of the heat sink leads to deterioration of the beam quality during far-field imaging of the cavity surface luminescence, increasing the difficulty and cost of optical system regulation.
A new type of heat sink with optical regulation function is adopted, including preparing a bar light bar on the top of the heat sink. The material is a visible light absorbing material, with a thickness smaller than the thickness of the laser chip, and a gap with the chip. The cross-sectional shape of the bar light bar is rectangular and positive. The trapezoidal or inverted trapezoidal shape is combined with the heat sink through deposition connection, and the electroplating film forming process is preferred.
Effectively blocks light emission in invalid areas, reduces light reflection, optimizes laser beam quality, reduces the risk of solder spillover during packaging, improves packaging yield, and solves the problem of beam quality degradation when cost controllable and process compatible.
Smart Images
Figure CN222261729U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lasers, in particular to a laser packaging structure. Background Art
[0002] The packaging of semiconductor chips has the functions of protection, support, connection, heat dissipation and reliability. Only strict working environment control, good support and fixation to facilitate circuit connection and mechanical protection of the appearance, enhanced heat dissipation and other measures can ensure the stability and service life of the chip. Therefore, packaging plays an important role in semiconductor chips. Semiconductor chip packaging technology is mostly developed and evolved on the basis of discrete device packaging technology. Different chip types have great particularity. Semiconductor laser packaging completes the output of electrical signals, protects the normal operation of the chip, and finally outputs the laser function. It has both electrical interconnection and chip protection, as well as optical output design and technical requirements. It is impossible to simply use discrete device packaging for semiconductor lasers.
[0003] A common semiconductor laser consists of a chip and packaging accessories. Taking TO packaging as an example, its accessories include a metal shell, a tube cap, an optical window and a heat sink. The shell plays a supporting and fixing role, as well as electrical interconnection and heat dissipation. The tube cap and the optical window play a role in protecting the working environment of the device and mechanical protection. The heat sink plays a role in heat dissipation and chip fixation and support and electrical interconnection. The general understanding of the heat sink is mainly the heat dissipation performance and mechanical properties, that is, the thermal conductivity and thermal expansion coefficient of the heat sink material, which directly affect the operating temperature of the chip and the stress it is subjected to, determine the stability and life of the device, and basically do not involve optical structure design. However, due to the high reflectivity of the laser light-emitting surface and the leakage mode of the laser epitaxial structure, its essence is that the luminous area of the laser spot is expanded under the limitation of the cavity mask waveguide, which seriously causes the entire light-emitting surface to emit light and degrade the beam quality in far-field imaging. The problem can be solved by the optical structure design of the heat sink and can be compatible with the manufacturing process of the heat sink. It can also be cost-controlled and is an effective solution to improve the laser beam quality. Utility Model Content
[0004] In view of the deficiencies of the prior art, the utility model provides a laser packaging structure, namely a heat sink with an optical structure, which solves the problem of far-field imaging of cavity surface emission caused by the waveguide effect of the light-emitting surface. At this time, an amplified cavity surface emission image will appear in the laser far field, which becomes stray light of the light source, which is not conducive to the collimation and focusing of the subsequent optical system, directly deteriorates the quality of the laser beam, increases the difficulty of optical system regulation, and increases the cost of use. Therefore, a laser packaging structure is proposed to solve the above-mentioned problems. To achieve the above purpose, the utility model provides the following technical solutions: a laser packaging structure, including a new optically regulated heat sink and a housing;
[0005] The optically regulated novel heat sink comprises a heat sink and a strip light barrier, the top of the heat sink is provided with a strip light barrier, the strip light barrier is located away from one end of the light emitting surface of the module and is located on the top of the heat sink, and a laser chip is fixedly installed;
[0006] The shell comprises a bracket, a heat sink fixing platform, electrode pins and a protective shell.
[0007] Furthermore, the strip light barrier is connected to the heat sink by deposition. The strip light barrier is deposited on the top of the heat sink. The cross-sectional shape of the strip light barrier parallel to the length direction of the laser chip cavity is a geometric figure. The cross-sectional shape of the strip light barrier can be a rectangle, a regular trapezoid, an inverted trapezoid, etc.
[0008] Furthermore, the thickness c of the strip light barrier is less than the thickness e of the laser chip, the thickness e of the laser chip is 70-150 μm, preferably e / 3≤c≤2e / 3, the strip light barrier does not hinder the outgoing light of the laser chip, there is a gap d between the strip light barrier and the laser chip, and the gap d is not less than 10 μm.
[0009] Furthermore, the material of the strip light barrier is a visible light absorbing material. ， The material of the strip light barrier is selected according to the lasing wavelength of the laser chip. For example, copper, silver, nickel and iron can be selected for visible light of 380nm-530nm.
[0010] Furthermore, the light contact surface of the strip light barrier is a rough surface, which can increase absorption and reduce light reflection.
[0011] Furthermore, the preparation of the strip light barrier is compatible with existing heat sink manufacturing technologies, such as PVD coating and electroplating, etc., preferably electroplating.
[0012] Furthermore, the optically controlled new heat sink is adapted to TO packaging, COB packaging, C / F-Mount packaging and plastic packaging, etc.
[0013] Compared with the prior art, the utility model provides a laser packaging structure, which has the following beneficial effects:
[0014] 1. The laser packaging structure, firstly, by preparing a strip light barrier on the top of the heat sink, the light emitting area of the invalid area of the light emitting surface of the laser chip can be effectively blocked, and the thickness c of the strip light barrier is less than the thickness e of the laser chip, so that the light in the invalid light emitting area of the cavity surface is blocked and absorbed without affecting the normal outward laser emission of the laser chip; secondly, the strip cross-sectional structure in the direction parallel to the cavity length can be rectangular, regular trapezoidal and inverted trapezoidal, etc., to reduce the reflection of the incident light; thirdly, the material of the strip light barrier is a visible light absorbing material. For example, copper, silver, nickel and iron can be selected for visible light of 380nm-530nm, which effectively absorbs the light emission in the invalid area and optimizes the laser beam quality. The light contact surface of the strip light barrier is preferably a rough surface, which can increase absorption and reduce reflection. In summary, compared with the traditional heat sink, the new packaging structure for the heat sink can effectively solve the problem of laser beam quality degradation caused by cavity surface emission under the condition of controllable cost and process compatibility.
[0015] 2. The laser packaging structure can reduce the risk of solder overflowing and connecting the laser chip with the strip light barrier during packaging by setting a gap d between the strip light barrier and the laser chip, thereby improving the packaging yield. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a structural cross-sectional view of the optically controlled new heat sink of the utility model;
[0017] Figure 2 This is a schematic diagram of the light emitted by the light-emitting surface film of a conventionally packaged laser;
[0018] Figure 3 This is a schematic diagram of light emission from the light-emitting surface film of the laser packaged in the utility model;
[0019] Figure 4 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;
[0020] Figure 5 This is a schematic diagram of the structure of Example 2 of the utility model.
[0021] In the figure: 1 optically controlled novel heat sink, 11 heat sink, 12 strip light barrier, 2 laser chip, 3 housing, 31 bracket, 32 heat sink fixing platform, 33 electrode pin, 34 protective shell. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0023] Embodiment 1:
[0024] TO package, please refer to Figure 1 and Figure 4 , a laser packaging structure, including a novel optically controlled heat sink 1 and a housing 3;
[0025] The optically controlled novel heat sink 1 comprises a heat sink 11 and a strip light barrier 12. The top of the heat sink 11 is provided with the strip light barrier 12. The laser chip 2 is fixedly mounted on the top of the heat sink 11 and the strip light barrier 12 is located away from one end of the light emitting surface of the module.
[0026] The housing 3 includes a bracket 31 , a heat sink fixing platform 32 , electrode pins 33 and a protective shell 34 .
[0027] In this embodiment, the strip light barrier 12 is connected to the heat sink 11 by deposition. The strip light barrier 12 is deposited on the top of the heat sink 11 by electroplating. The cross-sectional shape of the strip light barrier 12 parallel to the cavity length direction of the laser chip 2 is a regular trapezoid.
[0028] In this embodiment, the thickness c of the strip light barrier 12 is smaller than the thickness e of the laser chip 2 , and there is a gap d between the strip light barrier 12 and the laser chip 2 , where e is 100 μm, c is 60 μm, and d is 20 μm.
[0029] In this embodiment, the strip light barrier 12 is made of copper material, which has a high absorption rate for visible light of 380nm-530nm.
[0030] In this embodiment, the light contact surface of the strip light barrier 12 is a rough surface, which can increase absorption and reduce light reflection.
[0031] In this embodiment, the housing 3 is a TO package housing, and the laser lasing wavelength is 450nm.
[0032] Embodiment 2:
[0033] Plastic package, please refer to Figure 1 and Figure 5 , a laser packaging structure, including a novel optically controlled heat sink 1 and a housing 3;
[0034] The optically regulated novel heat sink 1 comprises a heat sink 11 and a strip light barrier 12. The top of the heat sink 11 is provided with the strip light barrier 12. The laser chip 2 is fixedly mounted on the top of the heat sink 11 and is located away from one end of the light emitting surface of the module.
[0035] In this embodiment, the strip light barrier 12 is connected to the heat sink 11 by deposition. The strip light barrier 12 is deposited on the top of the heat sink 11 by electroplating. The cross-sectional shape of the strip light barrier 12 parallel to the cavity length direction of the laser chip 2 is an inverted trapezoid.
[0036] In this embodiment, the thickness c of the strip light barrier 12 is smaller than the thickness e of the laser chip 2 , and there is a gap d between the strip light barrier 12 and the laser chip 2 , where e is 100 μm, c is 80 μm, and d is 20 μm.
[0037] In this embodiment, the strip light barrier 12 is made of copper material, which has a high absorption rate for visible light of 380nm-530nm.
[0038] In this embodiment, the light contact surface of the strip light barrier 12 is a rough surface, which can increase absorption and reduce light reflection.
[0039] In this embodiment, the housing 3 is a plastic package housing, and the laser lasing wavelength is 510 nm.
[0040] The beneficial effects of the above embodiments are:
[0041] The laser packaging structure, firstly, by preparing a strip light barrier 12 on the top of the heat sink 11, the light emission of the invalid area of the light-emitting surface of the laser chip 2 can be effectively blocked, and the thickness c of the strip light barrier 12 is less than the thickness e of the laser chip 2, so that the invalid light emission of the cavity surface is blocked and absorbed without affecting the normal outward laser emission of the laser chip 2; secondly, the strip cross-sectional structure in the direction parallel to the cavity length can be rectangular, regular trapezoidal, inverted trapezoidal, etc., to reduce the reflection of the incident light; thirdly, the material of the strip light barrier 12 is an excellent absorber of the emitted laser, for example, copper, silver, nickel and iron can be selected for visible light of 380nm-530nm, which effectively absorbs the light emission of the invalid area and optimizes the laser beam quality, and the light contact surface of the strip light barrier 12 is preferably a rough surface, and the rough structure of the light contact surface can increase absorption and reduce reflection. In summary, compared with the traditional heat sink, the new packaging structure for the heat sink 11 can effectively solve the problem of laser beam quality degradation caused by cavity surface emission under the condition of controllable cost and process compatibility.
[0042] The laser packaging structure can reduce the risk of solder overflowing and connecting the laser chip 2 and the strip light barrier 12 during packaging by setting a gap d between the strip light barrier 12 and the laser chip 2, thereby improving the packaging yield.
[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.
[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A laser packaging structure, comprising a novel optically controlled heat sink (1) and a housing (3), characterized in that: The optically controlled novel heat sink (1) comprises a heat sink (11) and a strip light barrier (12), wherein the top of the heat sink (11) is provided with the strip light barrier (12), and the strip light barrier (12) is located away from one end of the light emitting surface of the module and is located on the top of the heat sink (11) and fixedly mounted with a laser chip (2); The housing (3) comprises a bracket (31), a heat sink fixing platform (32), electrode pins (33) and a protective shell (34).
2. A laser packaging structure according to claim 1, characterized in that: The strip light barrier (12) and the heat sink (11) are connected in a deposition connection manner, and the cross-sectional shape of the strip light barrier (12) parallel to the cavity length direction of the laser chip (2) is a geometric figure.
3. The laser packaging structure according to claim 1, characterized in that: The thickness of the strip light barrier (12) is smaller than the thickness of the laser chip (2); the strip light barrier (12) does not obstruct the emitted light of the laser chip (2); and there is a gap between the strip light barrier (12) and the laser chip (2).
4. The laser packaging structure according to claim 1, characterized in that: The material of the strip light barrier (12) is a visible light absorbing material.
5. The laser packaging structure according to claim 1, characterized in that: The light contact surface of the strip light barrier (12) is a rough surface.
6. The laser packaging structure according to claim 1, characterized in that: The preparation of the strip light barrier (12) is compatible with the existing heat sink (11) manufacturing technology.
7. The laser packaging structure according to claim 1, characterized in that: The novel optically controlled heat sink (1) is suitable for TO packaging, COB packaging, C / F-Mount packaging and plastic packaging.