Destressing bar packaging array and laser

Abstract

The invention relates to a destressing bar packaging array and a laser. The destressing bar packaging array comprises a plurality of laser bar modules, an insulating base and a plurality of conductive elements, the plurality of conductive elements are arranged on the surface of the insulating base at intervals; and the laser bar modules are mutually independent and are electrically connected with two adjacent conductive elements respectively, so that the plurality of laser bar modules are electrically connected in series. According to the invention, on the basis that the conductive elements are electrically connected with the laser bar modules, that is, the laser bar modules are not connected, quality defects caused by packaging stress can be reduced in the packaging process, so that the product packaging qualification rate reaches 99% or above, and stable use can be realized when the pulse width is 100 milliseconds and the duty ratio is 40% or above; the structure is simple, packaging is convenient, and mass production is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a stress relief bar package array and a laser. Background Art

[0002] Semiconductor lasers are widely used due to their advantages of high power, high brightness, and small size. In recent years, with the development of the industry, application areas have placed higher demands on semiconductor lasers. High duty cycle, pulse width of hundreds of milliseconds, and gold-tin packaging have gradually replaced continuous indium packaging technology. The technological development of semiconductor lasers has become increasingly mature and stable. At the same time, the replacement of indium packaging with gold-tin packaging has also posed new technical challenges to the industry. Gold-tin alloy is a hard solder. Compared with indium metal, which is known for its soft solder, its introduction brings high reliability performance to lasers but also brings greater stress and thermal stress problems to laser packaging. In particular, in some semiconductor laser arrays with pulse widths of hundreds of milliseconds and duty cycles exceeding 40%, packaging stress and thermal stress frequently cause chip cracking and burning during the packaging process and testing, causing great trouble to the life reliability and packaging qualification rate of semiconductor laser arrays. The above problems need to be solved urgently. Summary of the Invention

[0003] The present invention discloses a stress relief bar package array and a laser, aiming to solve the technical problems existing in the prior art.

[0004] The present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a stress relief bar package array comprising a plurality of laser bar modules, an insulating base, and a plurality of conductive elements; the plurality of conductive elements are spaced apart on a surface of the insulating base; the laser bar modules are independent of one another and are electrically connected to two adjacent conductive elements, respectively, to form a series electrical connection between the plurality of laser bar modules.

[0006] In the stress relief bar package of the present invention, the laser bar module includes a first heat sink, a bar, and a second heat sink; the first heat sink is welded to one side of the bar through a first welding material layer, and is welded to one of the adjacent conductive elements through a second welding material layer; the second heat sink is welded to the other side of the bar through the first welding material layer, and is welded to the other adjacent conductive element through the second welding material layer.

[0007] In the stress relief bar package of the present invention, the first solder layer is a gold-tin solder layer with a thickness of 4 micrometers to 8 micrometers.

[0008] In the stress relief bar package of the present invention, the first solder material layer is a gold-tin solder layer, and the mass ratio of gold to tin in the gold-tin solder layer is 80±5%:20±5%.

[0009] In the stress relief bar package of the present invention, the second solder layer is a tin-silver-copper solder layer with a thickness of 12-50 microns.

[0010] In the stress relief bar package of the present invention, the opposite edges of adjacent conductive elements are parallel to form an insulating area; the insulating base is provided with an insulating through-groove at a position corresponding to the insulating area; and the bar of the laser bar module is located directly above the insulating through-groove.

[0011] In the stress relief bar package of the present invention, the interval between adjacent laser bar modules is greater than or equal to 0.

[0012] In the stress relief bar package of the present invention, a stress buffer structure is filled between adjacent conductive elements.

[0013] In the stress relief bar package of the present invention, the conductive element is a metal conductive layer.

[0014] In the stress relief bar package of the present invention, the insulating base is a plate-shaped structure made of ceramic material, and the conductive elements are respectively provided on both side surfaces.

[0015] In a second aspect, the present invention further provides a laser comprising any of the above-mentioned stress relief bar package arrays and a laser heat sink; the insulating base is welded to the laser heat sink via a third welding material layer.

[0016] In the laser of the present invention, the third solder layer is an indium or indium tin solder layer.

[0017] The laser of the present invention comprises a plurality of the stress relief bar package arrays; the stress relief bar package arrays are electrically connected in series.

[0018] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0019] The present invention mainly provides a stress-relief bar package array. Based on the electrical connection between conductive elements and laser bar modules, that is, the laser bar modules are not connected to each other, the quality defects caused by packaging stress can be reduced during the packaging process, so that the product packaging qualification rate reaches more than 99%, and stable use can be achieved with a pulse width of 100 milliseconds and a duty cycle of more than 40%. It has a simple structure, convenient packaging, and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0021] Figure 1 This is a schematic structural diagram of a stress relief bar packaging array according to the present invention;

[0022] Figure 2 Schematic diagram of the three-dimensional structure of the laser of the present invention;

[0023] Figure 3 Schematic diagram of the internal structure of the laser heat sink of the present invention;

[0024] Figure 4 Schematic diagram of the internal structure of the laser heat sink of the present invention;

[0025] Figure 5 Schematic diagram of the main structure of the laser of the present invention;

[0026] Figure 6 It is a schematic cross-sectional structural diagram of the laser of the present invention.

[0027] Description of reference numerals:

[0028] 1. Laser bar module; 11. First heat sink; 12. Bar; 13. Second heat sink; 2. Insulating base; 21. Insulating slot; 3. Conductive element; 4. Insulating area; 5. Laser heat sink; 51. Heat sink body; 511. Cooling channel; 512. Inlet; 513. Outlet; 514. Flow guide; 52. First electrode; 53. Second electrode; 54. First insulating PCB board; 55. Second insulating PCB board. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. In the description of the present invention, it should be noted that the term "or" is generally used in the sense of including "and / or" unless the content clearly indicates otherwise.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly specified and limited.

[0031] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] To solve the problems existing in the prior art, embodiments of the present application provide a stress-relief bar package array and a laser.

[0033] Example 1

[0034] This embodiment provides a stress relief bar package array, such as Figure 1 As shown, the stress relief bar package array A includes multiple laser bar modules 1, an insulating base 2 and multiple conductive elements 3; the multiple conductive elements 3 are arranged at intervals on the surface of the insulating base 2; the laser bar modules 1 are independent of each other, and are electrically connected to two adjacent conductive elements 3 to form a series electrical connection between the multiple laser bar modules 1.

[0035] The stress-relief bar package array of the present invention electrically connects the conductive element 3 to the laser bar module 1, i.e., the laser bar modules are not connected to each other. This reduces quality defects caused by packaging stress during the packaging process, achieving a product packaging qualification rate of over 99%. Furthermore, the array can achieve stable operation with a pulse width of 100 milliseconds and a duty cycle of over 40% (tested at 25°C and a water flow rate of 2 L / M). The array also has a simple structure, is easy to package, and is suitable for mass production.

[0036] In some preferred embodiments, a plurality of laser bar modules 1 are arranged in parallel.

[0037] In some preferred embodiments, the laser bar module 1 includes a first heat sink 11, a bar 12 and a second heat sink 13; the first heat sink 11 is welded to one side of the bar 12 through a first welding material layer, and is welded to one of the adjacent conductive elements 3 through a second welding material layer; the second heat sink 13 is welded to the other side of the bar 12 through the first welding material layer, and is welded to the other adjacent conductive element 3 through the second welding material layer; the bar 12 is clamped by the first heat sink 11 and the second heat sink 13, which is beneficial to cooling the bar 12; the materials of the first heat sink 11 and the second heat sink 13 can be the same or different; a first-level package is formed by welding the first heat sink 11, the bar 12 and the second heat sink 13 through the first welding material layer, and a reflow oven can be used for reflow soldering, or a placement machine can be used for it; after the first-level package, the second-level package is welded to the conductive element 3 through the second welding material layer to form a second-level package, and a reflow oven can be used for reflow soldering of the second-level package.

[0038] Preferably, the material of the first heat sink 11 and the second heat sink 13 can be selected from tungsten copper, such as W90Cu10, diamond copper or metallized aluminum nitride ceramic; further preferably, the material is diamond copper, which has the best heat dissipation effect.

[0039] Preferably, the surfaces of the first heat sink 11 and the second heat sink 13 are plated with nickel-gold or titanium-platinum-gold; thereby, solderability and conductivity are increased, and solder is prevented from diffusing into the interior of the heat sink during soldering.

[0040] Preferably, the melting point of the first welding material layer is greater than that of the second welding material layer to prevent the first welding material layer from melting during the welding process.

[0041] In some preferred embodiments, the first solder layer is a gold-tin solder layer with a thickness of 4 to 8 microns; based on this, the normal operation of the laser can be guaranteed; when the thickness is lower than the lower limit, there will be voids in the welding, and the laser will fail during use; when the thickness is higher than the upper limit, the packaged solder will overflow, and the solder will block the functional area, that is, the laser light output area, causing product failure.

[0042] In some preferred embodiments, the first solder layer is a gold-tin solder layer, and the mass ratio of gold to tin in the gold-tin solder layer is 80±5%:20±5%. Within this range, the performance of the laser can be guaranteed. If the ratio exceeds the range, the packaging temperature will increase, resulting in increased product stress and reduced product life.

[0043] In some preferred embodiments, the second solder layer is a tin-silver-copper solder layer with a thickness of 12-50 microns. Within this range, the stress relief effect is good. Outside the range, it will cause poor welding and poor stress relief. If the thickness is too thin, it will cause poor welding or voids. The presence of voids will cause thermal expansion coefficient mismatch and generate stress. If the thickness is too thick, it will cause solder flow and easily affect the insulation area. Further preferably, the weight ratio of the components of the tin-silver-copper solder layer is: tin (Sn): silver (Ag): copper (Cu) = 96.5:3:0.5. Based on this, the welding temperature is more accurate during welding, and the control of the welding area is easier, thereby ensuring the stress relief effect.

[0044] In some preferred embodiments, the relative edges of adjacent conductive elements 3 are parallel to form an insulating region 4; an insulating through-slot 21 is provided at a position of the insulating base 2 corresponding to the insulating region 4; the bar 12 of the laser bar module 1 is located directly above the insulating through-slot 21 and is arranged parallel to the insulating through-slot 21; based on the provision of the insulating through-slot 21, the insulation performance can be improved and the stress relief effect can be enhanced.

[0045] In some preferred embodiments, the interval between adjacent laser bar modules 1 is greater than or equal to 0; preferably, the interval is greater than 0; specifically, the size of the interval is determined according to the design requirements of the working conditions. If the product size is sufficient and the required power is small, the interval can be increased to facilitate packaging; if the product size is insufficient and the required power is large, the interval is reduced to increase the width of the first heat sink 11 and the second heat sink 13 to improve the heat dissipation performance.

[0046] In some preferred embodiments, a stress buffer structure is filled between adjacent conductive elements 3. The stress buffer structure is made of a heat-conducting material and / or a conductive material, or other high-temperature resistant material, to ensure that no contamination is generated during operation. The heat-conducting and / or conductive material is provided to increase the conductive or heat-conducting area of the laser and improve the heat dissipation effect.

[0047] Preferably, the material of the stress buffer structure is indium-based solder, or indium metal, indium-tin alloy metal, thermal grease, silicone and other softer materials. Further preferably, the material of the stress buffer structure is indium metal, so as to improve the thermal conductivity without affecting the stress relief effect.

[0048] In some preferred embodiments, the conductive element 3 is a metallic conductive layer.

[0049] Preferably, the metal conductive layer is a copper layer with a nickel-gold plated surface; the thickness of the copper layer is determined by the magnitude of the laser operating current; specifically, it can be determined by referring to data such as the cross-sectional area of the conductive material corresponding to the current.

[0050] Preferably, the plurality of conductive elements 3 can be formed by cutting grooves on the insulating base 2 plated with a metal layer.

[0051] In some preferred embodiments, the insulating base 2 is a plate-like structure made of ceramic material, and conductive elements 3 are respectively provided on both side surfaces; preferably, the insulating base 2 is made of aluminum nitride ceramic to improve thermal conductivity.

[0052] Example 2

[0053] This embodiment provides a laser, such as Figure 2-Figure 5 As shown, it includes the stress relief bar package array A and the laser heat sink 5 in the above-mentioned embodiment 1; the insulating base 2 is welded to the laser heat sink 5 through a third welding material layer; the laser can be used as a side pump source surrounding the crystal rod, and can also be combined into a planar array for end pumping.

[0054] In some preferred embodiments, the third solder layer is an indium or indium tin solder layer, and its melting point is close to that of the second solder layer.

[0055] In some preferred embodiments, multiple stress relief bar package arrays are included; the stress relief bar package arrays are electrically connected in series; for example, the current series connection between the multiple stress relief bar package arrays is achieved by bridging electrodes, gold wire bonding, etc.

[0056] In some preferred embodiments, the laser heat sink 5 includes a heat sink body 51, a first electrode 52, a second electrode 53, a first insulating PCB board 54, and a second insulating PCB board 55. The heat sink body 51 has a cooling channel 511 extending along the arrangement of the bars 12 of the stress relief bar package array, with an inlet 512 formed on one side of the heat sink body 51 and an outlet 513 formed on the opposite side. The stress relief bar package array is disposed on the top surface of the heat sink body 51. The first insulating PCB board 54 and the second insulating PCB board 55 are fixed to the side of the heat sink body 51 adjacent to the top surface. The first electrode 52 is welded to the first insulating PCB board 54 via a fourth solder layer, and the second electrode 53 is welded to the second insulating PCB board 55 via a fourth solder layer. Furthermore, preferably, multiple flow guides 514 are disposed within the cooling channel 511. The multiple flow guides 514 are staggered to create turbulent flow in the cooling medium, thereby enhancing heat exchange.

[0057] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A stress relief bar package array, characterized in that: It includes multiple laser bar modules, an insulating base and multiple conductive elements; A plurality of the conductive elements are spaced apart and arranged on the surface of the insulating base; The laser bar modules are independent of each other and are electrically connected to two adjacent conductive elements respectively, so as to form a series electrical connection between the plurality of laser bar modules.

2. The stress relief bar package array according to claim 1, characterized in that: The laser bar module includes a first heat sink, a bar and a second heat sink; The first heat sink is welded to one side of the bar through a first welding material layer, and is welded to one of the adjacent conductive elements through a second welding material layer; The second heat sink is welded to the other side of the bar through a first welding material layer, and is welded to another adjacent conductive element through a second welding material layer.

3. The stress relief bar package array according to claim 2, characterized in that: The first solder material layer is a gold-tin solder layer with a thickness of 4 microns to 8 microns.

4. The stress relief bar package array according to claim 2, characterized in that: The first solder material layer is a gold-tin solder layer, and the mass ratio of gold to tin in the gold-tin solder layer is (80±5%):.

5. The stress relief bar package array according to claim 2, characterized in that: The second solder layer is a tin-silver-copper solder layer with a thickness of 12-50 microns.

6. The stress relief bar package array according to any one of claims 1 to 5, characterized in that: Opposite edges of adjacent conductive elements are parallel to form an insulating region; The insulating base is provided with an insulating through groove at a position corresponding to the insulating area; The bar of the laser bar module is located directly above the insulating through groove.

7. The stress relief bar package array according to any one of claims 1 to 5, characterized in that: The interval between adjacent laser bar modules is greater than or equal to 0.

8. The stress relief bar package array according to any one of claims 1 to 5, characterized in that: A stress buffer structure is filled between adjacent conductive elements.

9. The stress relief bar package array according to any one of claims 1 to 5, characterized in that: The conductive element is a metal conductive layer.

10. The stress relief bar package array according to any one of claims 1 to 5, characterized in that: The insulating base is a plate-shaped structure made of ceramic material, and the conductive elements are respectively arranged on both side surfaces.

11. A laser, characterized in that: The stress relief bar package array and the laser heat sink are included in any one of claims 1 to 10; The insulating base is welded to the laser heat sink through a third welding material layer.

12. The laser according to claim 11, characterized in that The third solder material layer is an indium or indium tin solder material layer.

13. The laser according to claim 11, characterized in that comprising a plurality of said stress relief bar package arrays; The stress relief bar package arrays are electrically connected in series.

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