Laser bar packaging unit and packaging method

Abstract

The present invention discloses a laser bar packaging unit and a packaging method. The bar packaging unit includes an integrated structure and an insulating heat conductive sheet bonded by a bottom solder layer. The integrated structure includes a P electrode, a laser bar and an N electrode arranged in sequence. The laser bar and the N electrode, as well as the laser bar and the P electrode, are bonded by the bar solder layer. The packaging method includes first packaging the laser bar, the N electrode and the P electrode into an integrated laser bar structure, and then welding the integrated laser bar structure with the insulating heat conductive sheet to package the laser bar packaging unit. The present invention uses the packaging of the laser bar as a separate process. Each laser bar is designed as an independent packaging unit, which is sintered separately. The quality performance is inspected before and after packaging. After passing the packaging, it is used as a unit element of the linear array packaging, which effectively ensures the packaging quality of the linear array and improves the packaging efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor lasers, and in particular relates to a laser bar packaging unit and a packaging method. Background Art

[0002] Laser Diode Bar, also known as semiconductor laser array chip, is a linear light source containing multiple light-emitting tube cores, shaped like Figures 1 to 4 The long thin chip shown in the figure has a chip length of about 10 mm, a height of (0.5-5) mm, a thickness of δ (0.1-0.15) mm, and two sides are as follows Figure 2 The P-pole surface (positive electrode) shown in Figure 3 The N-pole surface (negative pole) shown in the figure has a light-emitting area located on an active area of ​​about 2um×10mm on the P-pole of the front cavity surface. The front cavity surface is coated with an anti-reflection film, and the rear cavity surface is coated with a high-reflection film. The cavity surface can be identified by the color of the coating.

[0003] The side pump laser head that provides high power specific wavelength pump source for high power solid laser is adopted Figures 1 to 4 The laser bar-packaged linear array shown in the figure is equipped with multiple groups of lasers that surround the working material for side pumping. The solid-state laser using the side-pumped laser head has a wide range of applications, such as scientific research, medical beauty, cleaning, marking and other metal processing fields.

[0004] The linear array is the main component of the side-pumped laser head. The packaging quality control of the laser bar is the key link in the packaging of the linear array. If any laser bar has poor packaging quality or performance, it will affect the light output performance and parameters of the entire linear array. In severe cases, it will cause the light output performance quality of the entire linear array to be unqualified or the electrical reliability to be low or even scrapped. It can be seen that the packaging quality and efficiency of the side-pumped laser head linear array are seriously affected by the packaging quality of a single laser bar. Summary of the invention

[0005] The present invention is proposed to solve the problem that the light output performance and reliability of the entire linear array of side-pumped laser heads are affected by the packaging quality of a single laser bar, and its purpose is to provide a laser bar packaging unit and a packaging method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A laser bar packaging unit includes an integrated structural member and an insulating thermal conductive sheet bonded by a bottom solder layer, wherein the integrated structural member includes a P electrode, a laser bar and an N electrode arranged in sequence, and the laser bar and the N electrode as well as the laser bar and the P electrode are bonded by the bar solder layer.

[0008] In the above technical solution, the insulating heat conductive sheet is bonded to the bottom surface of the integrated structural member; the P electrode is bonded to the P pole surface of the laser bar, and the N electrode is bonded to the N pole surface of the laser bar.

[0009] In the above technical solution, an N-electrode boss is formed on one side of the packaging surface of the N-electrode, and a chamfer is formed on the other side. The chamfer and the N-electrode boss are both formed on the top surface of the N-electrode; a P-electrode boss is formed on one side of the packaging surface of the P-electrode.

[0010] In the above technical solution, the length, width and thickness of the N-electrode boss and the P-electrode boss are the same, and the length and width of both are 1.05 to 1.15 times the length and width of the laser bar; the thickness of both is 1 to 2 times the thickness δ of the laser bar.

[0011] In the above technical solution, the P electrode and the N electrode are both made of red copper, oxygen-free copper or tungsten copper.

[0012] In the above technical solution, the top surface of the insulating thermally conductive sheet forms an electrical isolation area along the long direction; the insulating thermally conductive sheet is made of aluminum nitride, silicon carbide, beryllium oxide or diamond, and the insulating thermally conductive sheet has a weldable metallized surface.

[0013] In the above technical solution, the bar solder layer adopts indium, gold tin or nano silver paste; the bottom solder layer adopts indium tin, indium lead or tin lead; the bar solder layer and the bottom solder layer are both in the form of any one of a solder sheet, a film or a solder paste.

[0014] In the above technical solution, the melting point of the bottom solder layer is at least 30° C. lower than the melting point of the bar solder layer.

[0015] A packaging method for a laser bar packaging unit comprises the following steps:

[0016] (I) Preparation of integrated structural parts

[0017] (i) stacking an N electrode, a bar solder layer, a laser bar, a bar solder layer, and a P electrode in sequence on a tooling groove; placing an integrated structural component welding block on the outer side of the P electrode, and assembling them on the tooling to form an integrated structural component preform;

[0018] (ii) placing the tooling carrying the prefabricated integrated structural component into a welding furnace, loading the process curve of the welding material of the bar solder layer, and packaging the laser bar, N electrode, and P electrode into an integrated structural component;

[0019] (II) Preparation of laser bar packaging unit

[0020] (i) placing an insulating heat conductive sheet, a bottom solder layer, and an integrated structural member on the tooling in sequence, placing a packaging unit welding block on the integrated structural member, and assembling on the tooling to form a laser bar packaging unit preform;

[0021] (ii) placing the tooling carrying the laser bar packaging unit preform into a welding furnace, loading the bottom solder layer welding material process curve, packaging the integrated structural component and the insulating thermal conductive sheet, and obtaining the laser bar packaging unit.

[0022] In the above technical solution, the welding furnace is a vacuum eutectic welding furnace or a reflow furnace.

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides a laser bar packaging unit and a packaging method, which solve the problem that the packaging quality and efficiency of a side-pumped laser head linear array are affected by the packaging quality of a single laser bar. The packaging of the laser bar is used as a separate packaging process for packaging a semiconductor laser side-pumped linear array, each laser bar is designed as an independent packaging unit, and is sintered using an independent fixture. Each laser bar can be inspected for quality and performance before and after packaging, and the laser bar packaging units that pass the test are used as unit elements of the linear array packaging. The batch welding and performance testing of the laser bar packaging units effectively ensure the packaging quality of the linear array and improve the packaging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a three-dimensional diagram of a laser bar in the present invention;

[0026] Figure 2 It is the front view (P pole surface) of the laser bar in the present invention;

[0027] Figure 3 is a rear view (N pole surface) of the laser bar in the present invention;

[0028] Figure 4 is a side view of the laser bar in the present invention (δ is thickness);

[0029] Figure 5 is a three-dimensional diagram of the N electrode in the present invention;

[0030] Figure 6 It is a rear view of the N electrode in the present invention (side packaging surface of the N electrode);

[0031] Figure 7 It is a right side view of the N electrode in the present invention;

[0032] Figure 8 is a three-dimensional diagram of the P electrode in the present invention;

[0033] Fig. 9 It is a rear view of the P electrode in the present invention (side packaging surface of the P electrode);

[0034] Fig.10 It is a right side view of the P electrode in the present invention;

[0035] Fig.11 is a three-dimensional diagram of the insulating thermal conductive sheet of the present invention;

[0036] Fig.12 It is a schematic diagram of the exploded structure of the integrated structural member in the present invention;

[0037] Fig.13 It is a schematic diagram of the integrated structural part of the present invention being assembled on the tooling;

[0038] Fig.14 It is a three-dimensional structural schematic diagram of the integrated structural member in the present invention;

[0039] Fig.15 It is a schematic diagram of the exploded structure of the laser bar packaging unit of the present invention;

[0040] Fig.16 It is a schematic diagram of the laser bar packaging unit of the present invention being assembled on a tooling;

[0041] Fig.17 It is a three-dimensional structural schematic diagram of the laser bar packaging unit of the present invention.

[0042] in:

[0043] 1 Laser Bar

[0044] 11P pole face 12N pole face

[0045] 2N Electrode

[0046] 21N electrode boss 22 chamfer

[0047] 3P electrode 31P electrode boss

[0048] 4 Insulation thermal conductive sheet 41 Electrical isolation area

[0049] 5 bar solder layer 6 bottom solder layer

[0050] 7 integrated structural parts 8 tooling

[0051] 9. Integrated structural component welding block 10. Packaging unit welding block.

[0052] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0054] like Figures 1 to 4 As shown, the present invention adopts a laser bar 1 that has passed the quality performance test, which is a long thin strip with a chip length of about 10 mm, a height of 0.5 mm to 5 mm, and a thickness δ of 0.1 mm to 0.15 mm. The two sides of the laser bar 1 are respectively a P-pole surface 11 as a positive electrode and an N-pole surface 12 as a negative electrode. The light-emitting area of ​​the laser bar 1 is located on an active area of ​​about 2um×10mm on the P-pole of the front cavity surface. The front cavity surface is coated with an anti-reflection film, and the rear cavity surface is coated with a high-reflection film. The cavity surface can be identified by the color of the coating.

[0055] Example 1

[0056] like Fig.15 , 17 As shown, a laser bar packaging unit includes an integrated structural member 7, an insulating thermal conductive sheet 4 and a bottom solder layer 6, wherein the bottom surface of the integrated structural member 7 is bonded to the top surface of the insulating thermal conductive sheet 4 through the bottom solder layer 6.

[0057] like Fig.12 , 14 As shown, the integrated structural component 7 includes a laser bar 1, an N electrode 2 and a P electrode 3, the P pole surface 11 of the laser bar 1 is bonded to the P electrode 3 through the bar solder layer 5, and the N pole surface 12 of the laser bar 1 is bonded to the N electrode 2 through the bar solder layer 5.

[0058] like Figures 5 to 7 As shown, an N-electrode boss 21 is formed on the upper portion of the side packaging surface of the N-electrode 2 close to the laser bar 1, and the length L and width H of the N-electrode boss 21 are 1.05 to 1.15 times the length and width of the laser bar 1, and the thickness of the N-electrode boss 21 is 1 to 2 times the thickness δ of the laser bar 1; a chamfer 22 is formed on the top edge of the side of the N-electrode 2 away from the laser bar 1.

[0059] like Figures 8 to 10 As shown, the P-electrode 3 forms a P-electrode boss 31 on the upper side packaging surface close to the laser bar 1, and the length L and width H of the P-electrode boss 31 are 1.05 times to 1.15 times the length and width of the laser bar 1, and the thickness of the P-electrode boss 31 is 1 times to 2 times the thickness δ of the laser bar 1.

[0060] The protruding structural design of the N-electrode boss 21 and the P-electrode boss 31 can achieve shape and position matching of the bonding of the N-electrode 2 and the P-electrode 3 with the laser bar 1, that is, the laser bar 1 is bonded to the N-electrode boss 21 and the P-electrode boss 31 through the bar solder layer 5.

[0061] The top edge of the N electrode 2 is chamfered, and the top edge of the P electrode 3 is kept at a right angle. The chamfer and the right angle mark make the laser bar unit have consistency in polarity direction after packaging.

[0062] The N electrode 2 and the P electrode 3 are made of red copper, oxygen-free copper or tungsten copper. In this embodiment, the N electrode 2 and the P electrode 3 are made of tungsten copper.

[0063] like Fig.11 As shown, the top surface of the insulating thermally conductive sheet 4 forms an electrical isolation area 41 along the long direction, and the electrical isolation area 41 divides the top surface of the insulating thermally conductive sheet 4 into two parts, that is, the top surface of the insulating thermally conductive sheet 4 has two weldable surface areas, which are respectively bonded to the bottom surfaces of the N electrode 2 and the P electrode 3 through two separate bottom solder layers 6; the bottom surface of the insulating thermally conductive sheet 4 is a full-width weldable surface.

[0064] The insulating heat-conducting sheet 4 is made of materials such as aluminum nitride, silicon carbide, beryllium oxide, diamond, etc. In this embodiment, the insulating heat-conducting sheet 4 is made of beryllium oxide.

[0065] The insulating heat-conducting sheet 4 is made of a weldable metalized surface such as titanium platinum, nickel gold or titanium nickel gold. In this embodiment, the insulating heat-conducting sheet 4 is made of a titanium platinum surface.

[0066] The bar solder layer 5 is made of indium, gold-tin or nano silver paste. The solder is in the form of a solder sheet, a film or a solder paste. In the present embodiment, the bar solder layer 5 is made of a gold-tin solder sheet.

[0067] The bottom solder layer 6 is made of indium tin, indium lead or tin-lead solder, and the solder is in the form of a solder sheet, a film or a solder paste. In the present embodiment, the bottom solder layer 6 is made of an indium-lead solder solder sheet.

[0068] The melting point of the bottom solder layer 6 is at least 30° C. lower than that of the bar solder layer 5 . In this embodiment, the melting point of the bottom solder layer 6 is 60° C. lower than that of the bar solder layer 5 , ensuring that the bar solder layer 5 will not melt during the second processing step.

[0069] Example 2

[0070] A packaging method for a laser bar packaging unit as described in Example 1 is completed by means of a tooling 8, an integrated structural member welding block 9 and a packaging unit welding block 10, wherein a right-angle V-shaped groove is formed on the top surface of the tooling 8, and the groove wall has one long side and a short side.

[0071] The specific packaging method includes the following steps:

[0072] (I) Preparation of integrated structural parts

[0073] The laser bar 1, N electrode 2, and P electrode 3 are packaged as one, specifically:

[0074] (i) selecting a high thermal conductivity conductive material and processing it into an N electrode and a P electrode of a desired shape;

[0075] (ii) selecting and manufacturing a bar solder layer suitable for bonding and packaging the two sides of the laser bar;

[0076] (iii) On the long side plane of the tooling groove, the N electrode, solder layer, laser bar, solder layer, and P electrode are stacked in sequence against the short side of the groove; the front light-emitting cavity surface of the laser bar is flush with the boss end surfaces of the N electrode and the P electrode on the long side plane of the tooling, that is, they are all in contact with the long side plane of the tooling groove to achieve flushness; an integrated structural component welding block 9 of appropriate weight is placed on the outside of the P electrode, and a combined prefabricated component of the laser bar, the N electrode, and the P electrode is assembled on the tooling;

[0077] (iv) placing the prefabricated assembly carrying the laser bar and the electrode into a welding furnace, loading the process curve of the welding material of the solder layer on both sides of the laser bar, and packaging the laser bar, the N electrode, and the P electrode into an integrated structural component;

[0078] (II) Preparation of laser bar packaging unit

[0079] The integrated structure 7 composed of the laser bar 1, the N electrode 2, and the P electrode 3 is packaged with the insulating heat conductive sheet 4 to obtain a laser bar packaging unit, specifically:

[0080] (i) Selecting insulating materials with high thermal conductivity and surface weldability to produce insulating thermally conductive sheets of required specifications;

[0081] (ii) selecting and manufacturing a bottom solder layer having good bonding performance between the areas on both sides of the electrical isolation area of ​​the insulating thermal conductive sheet and the bottom surface of the N electrode and the bottom surface of the P electrode;

[0082] (iii) placing an insulating heat-conducting sheet on the long side plane of the tooling groove against the right-angled short side with the dividing area facing upward, and the bottom solder layer is respectively attached to the upper surface of the areas on both sides of the electrical isolation area; placing the packaged integrated structure 7 on the two bottom solder layers, placing a packaging unit welding block 10 of appropriate weight on the top of the integrated structure, and assembling on the tooling to form a laser bar packaging unit preform;

[0083] (iv) placing the tooling carrying the laser bar package unit preform into a welding furnace, loading the solder layer welding material process curve, and packaging the integrated structural part and the insulating thermal conductive sheet into the laser bar package unit of the present invention.

[0084] The laser bar packaging unit is packaged in a vacuum eutectic welding furnace or a reflow furnace. In this embodiment, the laser bar packaging unit is packaged in a vacuum eutectic welding furnace.

[0085] The laser bar packaging unit in the present invention can be set as a separate packaging process for packaging the semiconductor laser side pump linear array, which has the process advantages of high packaging efficiency and consistent and controllable packaging quality, effectively ensuring the packaging quality of the linear array and improving the packaging efficiency.

[0086] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0087] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A laser bar packaging unit, Features: The invention comprises an integrated structural member (7) and an insulating heat conductive sheet (4) bonded by a bottom solder layer (6), wherein the integrated structural member (7) comprises a P electrode (3), a laser bar (1) and an N electrode (2) arranged in sequence, and the laser bar (1) and the N electrode (2) as well as the laser bar (1) and the P electrode (3) are bonded by the bar solder layer (5); The insulating heat conductive sheet (4) is bonded to the bottom surface of the integrated structural member (7); the P electrode (3) is bonded to the P pole surface (11) of the laser bar (1), and the N electrode (2) is bonded to the N pole surface (12) of the laser bar (1); An N-electrode boss (21) is formed on one side of the packaging surface of the N-electrode (2), and a chamfer (22) is formed on the other side of the edge, and the chamfer (22) and the N-electrode boss (21) are both formed at the top end of the N-electrode (2); and a P-electrode boss (31) is formed on one side of the packaging surface of the P-electrode (3).

2. The laser bar packaging unit according to claim 1, Features: The N-electrode boss (21) and the P-electrode boss (31) are of the same length, width and thickness, and the length and width of both are 1.05 to 1.15 times the length and width of the laser bar (1); the thickness of both is 1 to 2 times the thickness δ of the laser bar (1).

3. The laser bar packaging unit according to claim 2, Features: The P electrode (3) and the N electrode (2) are both made of red copper, oxygen-free copper or tungsten copper.

4. The laser bar packaging unit according to claim 1, Features: The top surface of the insulating heat-conducting sheet (4) forms an electrical isolation area (41) along the length direction; the insulating heat-conducting sheet (4) is made of aluminum nitride, silicon carbide, beryllium oxide or diamond, and the insulating heat-conducting sheet (4) has a weldable metallized surface.

5. The laser bar packaging unit according to claim 1, Features: The bar solder layer (5) is made of indium, gold tin or nano silver paste; the bottom solder layer (6) is made of indium tin, indium lead or tin lead; the bar solder layer (5) and the bottom solder layer (6) are both in the form of any one of a solder sheet, a film or a solder paste.

6. The laser bar packaging unit according to claim 5, Features: The melting point of the bottom solder layer (6) is at least 30° C. lower than the melting point of the bar solder layer (5).

7. A packaging method for a laser bar packaging unit, Features: The following steps are involved: (I) Preparation of integrated structural parts (i) stacking an N electrode, a bar solder layer, a laser bar, a bar solder layer, and a P electrode in sequence on a tooling groove; placing an integrated structural component welding block on the outer side of the P electrode, and assembling them on the tooling to form an integrated structural component preform; (ii) placing the tooling carrying the prefabricated integrated structural component into a welding furnace, loading the process curve of the welding material of the bar solder layer, and packaging the laser bar, N electrode, and P electrode into an integrated structural component; An N-electrode boss is formed on one side of the packaging surface of the N-electrode, and a chamfer is formed on the other side of the edge, and the chamfer and the N-electrode boss are both formed on the top surface end of the N-electrode; a P-electrode boss is formed on one side of the packaging surface of the P-electrode; (II) Preparation of laser bar packaging unit (i) placing an insulating heat conductive sheet, a bottom solder layer, and an integrated structural member on the tooling in sequence, placing a packaging unit welding block on the integrated structural member, and assembling on the tooling to form a laser bar packaging unit preform; (ii) placing the tooling carrying the laser bar packaging unit preform into a welding furnace, loading the bottom solder layer welding material process curve, packaging the integrated structural component and the insulating thermal conductive sheet, and obtaining the laser bar packaging unit.

8. The packaging method of the laser bar packaging unit according to claim 7, Features: The welding furnace is a vacuum eutectic welding furnace or a reflow furnace.

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