Edge-emitting laser planar packaging structure and manufacturing method and application thereof

Abstract

The invention relates to an edge-emitting laser planar packaging structure and a manufacturing method and application thereof. The plane packaging structure of the edge-emitting laser comprises a positive substrate composed of a conductive substrate I and an insulating part A and a negative substrate composed of a conductive substrate II and an insulating part B. The negative substrate is reversely buckled on the positive substrate to form a cavity, and a COS bottom surface formed by a laser chip and a heat sink is fixed on the conductive substrate I and is conducted. And the N surface of the laser chip is conducted with the conductive substrate II of the negative substrate, and the output laser of the laser chip is vertical to the light passing surface of the cavity and is emitted. According to the invention, the problems of blurred light spots and expensive packaging are solved, and the adjustment of a plurality of light emitting directions can be conveniently realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor laser packaging, and in particular relates to a planar packaging structure of an edge-emitting laser, a manufacturing method and an application thereof. Background Art

[0002] Semiconductor lasers (LD lasers) have the advantages of small size, light weight, long life, high operational reliability, low energy consumption, high electro-optical conversion efficiency, easy large-scale production and low price. They are widely used in optical communications, optical storage, optical pumping, optical indication and other fields. In recent years, with the advancement of technology and the improvement of people's living standards, the laser therapy market has developed rapidly. Applications such as laser hair growth caps require dozens or even hundreds of lasers to work together. Semiconductor edge-emitting lasers emit light in a direction parallel to the substrate surface, which places higher requirements on the laser packaging volume. The packaging structures of edge-emitting semiconductor lasers are mainly TO packaging, plastic-encapsulated bracket packaging, and LED bracket packaging. Conventional semiconductor edge-emitting lasers are generally TO packages, which have larger package dimensions and are difficult to automate during assembly, resulting in low efficiency. However, the market demand for low-cost, miniaturized, flat-packaged lasers is increasingly strong.

[0003] Chinese patent CN208461199U discloses a side-emitting laser package structure, comprising a PCB, a heat sink, an LD chip, and a metal housing. The heat sink is horizontally fixed to the copper foil layer on the PCB, and the LD chip is also horizontally fixed to the heat sink. Light-emitting holes are provided at corresponding locations on the side of the housing, and the LD chip is connected to the PCB via gold wire. This achieves a package structure in which the laser's light emission direction is parallel to the PCB pads, eliminating the need for mechanical bending of the TO tube and extending the life of the LD chip.

[0004] Chinese patent document CN106207741A discloses a laser packaging structure and its optical element, which realizes the SMD plane packaging (Surface Mount Device) of the edge-emitting laser by setting a reflector inside the laser, also known as surface mounting. However, in actual production, due to the complex manufacturing process of the reflector and the difficulty in controlling the roughness of the reflecting surface, there is a disadvantage of the product light spot being blurred, and there is also the problem of excessively high product cost. In order to solve the shortcomings of the product light spot being blurred and the packaging cost being expensive of this solution, the present invention is specially proposed. Summary of the Invention

[0005] In view of the shortcomings of the existing planar packaging technology, the present invention provides an edge-emitting laser planar packaging structure and a preparation method and application to solve the problems of blurred light spots and high packaging costs of existing planar packaging products.

[0006] One of the purposes of the present invention is to provide a planar packaging structure for an edge-emitting laser, which can realize laser side emission without using a reflector, thereby solving the problems of blurred light spot and expensive packaging.

[0007] A second object of the present invention is to provide a method for manufacturing a planar packaging structure of an edge-emitting laser, which is simple and safe to operate.

[0008] A third object of the present invention is to provide an application of a planar packaging structure for an edge-emitting laser.

[0009] The technical solutions of the present invention are as follows:

[0010] An edge-emitting laser planar packaging structure, comprising:

[0011] The positive substrate is composed of a conductive substrate I and an insulating component A. The insulating component A is fixed on the edge of the conductive substrate I.

[0012] The negative substrate is composed of a conductive substrate II and an insulating component B, and the insulating component B is fixed on the edge of the conductive substrate II;

[0013] The negative substrate is inverted on the positive substrate to form a cavity, the insulating component A is bonded to the insulating component B, and at least one side of the cavity is a light-transmitting surface;

[0014] The COS is formed by a laser chip and a heat sink. The bottom surface of the COS is fixed on the conductive substrate I of the positive substrate in the cavity and is conductive, so that the N surface of the laser chip on the heat sink is conductive with the conductive substrate II of the negative substrate. The output laser of the laser chip is perpendicular to the light-transmitting surface of the cavity.

[0015] According to the present invention, the conductive substrate I is a conductive high-heat dissipation material such as oxygen-free copper or Kovar alloy; the conductive substrate II is a conductive high-heat dissipation material such as oxygen-free copper or Kovar alloy; the conductive substrate I and the conductive substrate II are made of the same or different materials.

[0016] According to the present invention, the insulating component A and the insulating component B are made of a material with good heat dissipation and non-conductivity, specifically selected from aluminum nitride, aluminum oxide or silicone grease, etc. The insulating component A and the insulating component B are made of the same or different materials.

[0017] According to a preferred embodiment of the present invention, the insulating component A is fixed to the conductive substrate I by means of non-conductive adhesive. The insulating component B is fixed to the conductive substrate II by means of non-conductive adhesive.

[0018] Preferably, according to the present invention, the insulating component A and the insulating component B are adapted in shape and size, and when the negative substrate is inverted onto the positive substrate, the insulating component A and the insulating component B are aligned up and down, so that the conductive substrate I of the positive substrate and the conductive substrate II of the negative substrate remain parallel.

[0019] According to a preferred embodiment of the present invention, the insulating component A is a U-shaped structure, fixed on the conductive substrate I to form a semi-enclosed structure with an opening on one side. The insulating component B is a U-shaped structure, fixed on the conductive substrate II to form a semi-enclosed structure with an opening on one side.

[0020] According to another preferred embodiment of the present invention, the insulating component A is a cube-shaped component fixed to two or three sides of the conductive substrate I, with the two insulating components A at the two ends being symmetrically arranged. Accordingly, the insulating component B is a cube-shaped component fixed to two or three sides of the conductive substrate II, with the two insulating components B at the two ends being symmetrically arranged. The cube shape includes a rectangular parallelepiped or a cube. Most preferably, the insulating components A and B have the same shape and size.

[0021] According to the present invention, the COS is fixed and electrically connected to the conductive substrate I of the positive substrate by conductive silver paste.

[0022] According to the present invention, the N side (negative electrode) of the laser chip is electrically connected to the conductive substrate II of the negative substrate via a conductive adhesive, which is preferably a conductive silver paste.

[0023] According to the present invention, the laser chip is an LD light-emitting chip.

[0024] In the packaging structure of the present invention, the positive electrode of the laser chip is connected to the conductive substrate I of the entire positive substrate through a heat sink, and the negative electrode (N side) of the laser chip is connected to the conductive substrate II of the entire negative substrate. When the customer subsequently solders the product to the PCB, soldering is performed from one of the side surfaces or surfaces of the conductive substrate I and conductive substrate II of the positive and negative substrates (except the light emitting direction of the laser chip), which greatly improves the product's mounting efficiency.

[0025] In a second aspect, the present invention further provides a method for manufacturing an edge-emitting laser planar packaging structure, comprising the steps of:

[0026] S1. Prepare the positive substrate and fix the insulating component A on the upper edge of the conductive substrate I using non-conductive adhesive;

[0027] S2. Prepare the negative substrate, and fix the insulating component B on the upper edge of the conductive substrate II using non-conductive adhesive;

[0028] S3, COS preparation, bonding the laser chip to the heat sink through gold-tin solder to form a COS, with the N side of the laser chip facing upward, and the heat sink can achieve upper and lower electrical conduction;

[0029] S4, COS bonding, bonding the COS to the conductive substrate I of the positive substrate through conductive silver paste;

[0030] S5. Packaging: Apply glue on the end face of the insulating component A of the positive substrate or apply glue on the end face of the insulating component B of the negative substrate, apply conductive silver paste on the N side (negative pole) of the laser chip, turn the negative substrate upside down, make the end face of the insulating component A meet the end face of the insulating component B, and connect the N side of the laser chip to the conductive substrate II of the negative substrate through the conductive silver paste to complete the buckling of the negative substrate and the positive substrate, and then bake to solidify the adhesive material.

[0031] Preferably, according to the present invention, the baking temperature is 145-155° C., and the baking time is 60-90 minutes.

[0032] According to the preferred embodiment of the present invention, the glue in step S5 is a non-conductive glue. Preferably, the non-conductive glue is selected from epoxy glue, polyurethane glue, etc.

[0033] Anything not described in detail in this specification can be based on the existing technology in this field.

[0034] In a third aspect, the present invention further provides an application of an edge-emitting laser planar packaging structure for manufacturing an edge-emitting laser module with an adjustable light emitting direction.

[0035] Specifically, with the exception of the laser chip's light-emitting side, all sides or surfaces of the conductive substrates I and II of the positive and negative substrates of the edge-emitting laser planar package structure of the present invention can serve as soldering surfaces to achieve laser emission in different directions. This allows for multiple changes in the light-emitting direction without the need for a reflector structure.

[0036] The welding surface mentioned in the present invention refers to the surface on which the packaged product is subsequently welded to the PCB, that is, a side surface or surface of the planar packaging structure of the edge-emitting laser of the present invention.

[0037] The technical features and beneficial effects of the present invention are:

[0038] The present invention provides a planar packaging structure for an edge-emitting laser. A cavity structure is formed by laminating two positive and negative conductive substrates to achieve planar packaging of the edge-emitting laser. In addition to the light emitting direction of the laser chip, several side surfaces and several directions of the upper and lower surfaces of the conductive substrates in the positive and negative substrates can be used as welding surfaces. Multiple changes in the light emitting direction can be achieved without providing a reflector structure, thus meeting customer application requirements for different light emitting directions and being very convenient.

[0039] The present invention not only realizes the flattened planar packaging of the product through structural optimization and improves the quality of the product's output light beam, but also the product can be welded from various sides and surfaces of the conductive substrate of the positive and negative substrates, greatly improving the product's mounting efficiency.

[0040] Furthermore, the edge-emitting laser planar package structure of the present invention connects the positive electrode of the laser chip to the conductive substrate I of the positive substrate, and the negative electrode to the conductive substrate II of the negative substrate, eliminating the need for gold wire bonding and significantly reducing product packaging costs. The edge-emitting laser planar package structure of the present invention simplifies edge-emitting laser packaging methods, facilitates various applications, and reduces the overall package size.

[0041] In the edge-emitting laser planar packaging structure of the present invention, since the reflector component and the cavity glue potting process are no longer used, the problem of blurred light spots caused by the glue potting and the rough surface of the reflector is solved.

[0042] The above is the packaging structure of a single edge-emitting laser of the present invention. In large-scale production, the positive and negative substrates can be connected as one piece, and after the whole is packaged, they can be cut and separated into individual pieces. This is simple and safe to operate, further reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic front view of the edge-emitting laser planar packaging structure monomer of the present invention.

[0044] Figure 2 This is a three-dimensional schematic diagram of the single-body model of the edge-emitting laser planar packaging structure.

[0045] Figure 3 Schematic diagram of the rear side of the conductive substrate serving as the welding surface.

[0046] Figure 4 The left side of the conductive substrate is used as a welding surface schematic diagram.

[0047] Figure 5 A picture of the light spot of a packaged rear-emitting laser according to one embodiment of the present invention.

[0048] In the figure, 1. positive substrate, 2. negative substrate, 3. laser chip, 4. heat sink, 5. conductive substrate I, 6. conductive substrate II, 7. positive substrate insulating component A, 8. negative substrate insulating component B, 9. conductive silver paste, 10. laser chip light outlet, 11. PCB (Printed Circuit Board), 12. positive electrode pad on PCB, 13. negative electrode pad on PCB; the direction indicated by the arrow in the figure is the light output direction. DETAILED DESCRIPTION

[0049] The present invention is further described below with reference to the following embodiments and accompanying drawings. However, this disclosure is not intended to limit the present invention. The described embodiments are merely a subset of the present invention. All other embodiments derived by persons of ordinary skill in the art based on these embodiments without inventive effort are intended to fall within the scope of protection of the present invention.

[0050] In the description of the present invention, it should be noted that the terms "upper," "lower," "left," "right," "inner," "outer," "front," and "back" and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of this invention, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, removable connections, or integral connections; they may refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this invention based on their specific circumstances. The term "conduction" refers to the transmission of current, signals, energy, etc. within a circuit.

[0052] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] All components used in the embodiments of the present invention are prior art. Kovar is a nickel-based alloy, an alloy of nickel, cobalt and iron, with a low thermal expansion coefficient and good welding performance.

[0054] One embodiment of the present invention, referring to Figure 1 、 Figure 2 A planar package structure for an edge-emitting laser is provided, comprising a positive substrate 1 and a negative substrate 2. The positive substrate 1 comprises a conductive substrate I 5 and an insulating component A 7. The insulating component A 7 is a U-shaped structure fixed to the conductive substrate I 5 to form a semi-enclosed structure with an opening on one side. The negative substrate 2 comprises a conductive substrate II 6 and an insulating component B 8. The insulating component B 8 is a U-shaped structure fixed to the conductive substrate II to form a semi-enclosed structure with an opening on one side. The negative substrate 1 is inverted and fastened to the positive substrate 2 to form a cavity. The opening on one side of the insulating component A 7 is aligned with the opening on the other side of the insulating component B 8 and bonded together. The aligned U-shaped openings of the insulating components A 7 and B 8 serve as the light-transmitting surface of the cavity.

[0055] The laser chip 3 is bonded to the heat sink 4 to form a COS. The bottom surface of the COS is fixed to the conductive substrate I5 of the positive substrate in the cavity through conductive silver paste and is connected. The N-side of the laser chip is connected to the conductive substrate II6 of the negative substrate through the conductive silver paste. The light output port 10 of the laser chip 3 faces the light-transmitting surface, and the output laser of the laser chip 3 is perpendicular to the light-transmitting surface of the cavity. The laser chip is an LD light-emitting chip.

[0056] Preferably, both conductive substrate I5 and conductive substrate II6 are made of oxygen-free copper. Insulating component A and insulating component B are both made of aluminum nitride. Insulating component A and insulating component B are bonded to conductive substrate I5 and conductive substrate II6, respectively, using a non-conductive epoxy adhesive. When the negative substrate is inverted and fastened to the positive substrate, insulating component A and insulating component B are aligned vertically and bonded using a non-conductive epoxy adhesive. The non-conductive adhesive can be epoxy or polyurethane adhesive.

[0057] The method for manufacturing a planar package structure of an edge-emitting laser in the above embodiment 1 includes the following steps:

[0058] (1) Positive substrate preparation

[0059] The insulating component A7 is fixed to the edges of the three sides of the conductive substrate I5 by bonding with non-conductive epoxy glue or polyurethane glue, and the edge component A7 is a U-shaped structure;

[0060] (2) Negative substrate preparation

[0061] The insulating component B is fixed to the edges of the three sides of the conductive substrate II 6 by bonding with non-conductive epoxy glue or polyurethane glue, and the edge component B 8 is a U-shaped structure;

[0062] (3) COS preparation

[0063] The laser chip 3 is bonded to the heat sink 4 by gold-tin solder to form a COS, with the N side of the laser chip facing upward. The heat sink 4 can achieve electrical conduction between the upper and lower parts. The COS is bonded to the conductive substrate I 5 of the positive substrate 1 by conductive silver paste, with the laser chip 3 facing upward.

[0064] (4) Encapsulation

[0065] Coat the end face of the insulating component A7 of the positive substrate 1 with non-conductive epoxy glue or polyurethane glue, or coat the end face of the insulating component B8 of the negative substrate 2 with non-conductive epoxy glue or polyurethane glue, coat the N side of the laser chip with conductive silver paste 9, turn the negative substrate 2 upside down, align the end face of the insulating component A7 with the end face of the insulating component B8, complete the buckling of the negative substrate 2 and the positive substrate 1, and then bake at 150±10℃ for 60 minutes to solidify the adhesive material.

[0066] The light spot picture of the package rear-emitting laser obtained according to the above embodiment 1 of the present invention is as follows Figure 5 As shown, the light spot is clear and the beam quality is good, which effectively solves the problem of blurred light spot of the existing edge-emitting laser.

[0067] According to the present invention, another preferred solution is that the conductive substrate I5 and the conductive substrate II6 are both made of Kovar alloy material.

[0068] Preferably, in another embodiment, the insulating component A and the insulating component B are made of materials selected from alumina or silicone grease.

[0069] Another embodiment of the present invention is as described above, except that the insulating components A7 and B8 are both rectangular parallelepiped-shaped and symmetrically disposed on the left and right sides of the conductive substrates I5 and II6, respectively. The sum of the heights of the insulating components A7 and B8 on the left and right sides is equal. The heights of the insulating components A7 on the left and right sides may be equal or unequal.

[0070] When the edge-emitting laser planar package structure of the above embodiment is subsequently applied, in addition to Figure 1 Aside from the front side of the laser chip, the remaining left, right, rear, and bottom surfaces of conductive substrate I5 of positive substrate 1 and the left, right, rear, and top surfaces of conductive substrate II6 of negative substrate 2 can serve as soldering surfaces for PCT. When soldering on different sides, the laser chip 3 of the edge-emitting laser emits light in different directions, enabling the transition of laser emission in different directions to meet the needs of different users and application scenarios. Several application examples are provided below.

[0071] For example, the rear side of the conductive substrate I5 of the positive substrate 1 and the rear side of the conductive substrate II6 of the negative substrate 2 are used as welding surfaces and are respectively welded to the positive pad and the negative pad on the PCB. The PCB board is perpendicular to the conductive substrate I5 and stands behind the positive and negative substrates. The light emitting direction of the laser chip 3 is parallel to the conductive substrate I5 and emits light forward. Figure 2 shown.

[0072] Another application method is to use the back side of the conductive substrate as the welding surface, such as Figure 3 As shown, Figure 1 The edge-emitting laser planar packaging structure is rotated 90° with the light-transmitting surface facing upward. The PCB board is located below the rear side of the conductive substrate I5 and the conductive substrate II6 (the PCB is at the bottom). The rear side of the conductive substrate I5 of the positive substrate 1 is welded to the positive pad on the PCB, and the rear side of the conductive substrate II6 of the negative substrate 2 is welded to the negative pad on the PCB, so that the light emitting direction of the laser chip 3 of the edge-emitting laser faces upward.

[0073] In the third aspect, the left side of the conductive substrate is used as the welding surface, such as Figure 4 As shown, the left side of the conductive substrate I5 of the positive substrate 1 is welded to the positive pad on the PCB, and the left side of the conductive substrate II6 of the negative substrate 2 is welded to the negative pad on the PCB. This allows the laser chip 3 of the edge-emitting laser to emit laser light to the left. Similarly, if the right side of the conductive substrate is used as the welding surface, the laser chip 3 of the edge-emitting laser can also emit laser light to the right.

[0074] Therefore, the edge-emitting laser planar packaging structure of the present invention not only has good light beam quality and low cost, but also can easily adjust the light output direction, thus meeting the needs of different customers and different application scenarios.

Claims

1. A planar package structure for an edge-emitting laser, comprising: The positive substrate is composed of a conductive substrate I and an insulating component A. The insulating component A is fixed on the edge of the conductive substrate I. The negative substrate is composed of a conductive substrate II and an insulating component B, and the insulating component B is fixed on the edge of the conductive substrate II; The negative substrate is reversely buckled to form a cavity on the positive substrate, the insulating component A is bonded to the insulating component B, and at least one side of the cavity is a light-transmitting surface; The COS is formed by a laser chip and a heat sink. The bottom surface of the COS is fixed on the conductive substrate I of the positive substrate in the cavity and is conductive, so that the N surface of the laser chip on the heat sink is conductive with the conductive substrate II of the negative substrate. The output laser of the laser chip is perpendicular to the light-transmitting surface of the cavity.

2. The edge-emitting laser planar packaging structure according to claim 1, characterized in that The conductive substrate I is a conductive high heat dissipation material such as oxygen-free copper or Kovar alloy; the conductive substrate II is a conductive high heat dissipation material such as oxygen-free copper or Kovar alloy; the conductive substrate I and the conductive substrate II are made of the same or different materials.

3. The edge-emitting laser planar packaging structure according to claim 1, characterized in that The insulating component A and the insulating component B are made of a material with good heat dissipation and non-conductivity, and are selected from aluminum nitride, aluminum oxide or silicone grease.

4. The edge-emitting laser planar packaging structure according to claim 1, characterized in that The insulating component A and the insulating component B are adapted in shape and size. When the negative substrate is inverted onto the positive substrate, the insulating component A and the insulating component B are aligned vertically, so that the conductive substrate I of the positive substrate and the conductive substrate II of the negative substrate remain parallel.

5. The edge-emitting laser planar packaging structure according to claim 1, characterized in that The insulating component A is a U-shaped structure, fixed on the conductive substrate I to form a semi-enclosed structure; the insulating component B is a U-shaped structure, fixed on the conductive substrate II to form a semi-enclosed structure.

6. The edge-emitting laser planar packaging structure according to claim 1, characterized in that The insulating component A is in a cube shape and is fixed on two or three sides of the conductive substrate I, wherein the two insulating components A on the two sides are symmetrically arranged; correspondingly, the insulating component B is in a cube shape and is fixed on two or three sides of the conductive substrate II, wherein the two insulating components B on the two sides are symmetrically arranged.

7. The edge-emitting laser planar packaging structure according to claim 1, characterized in that The COS is fixed and connected to the conductive substrate I of the positive substrate through conductive silver paste.

8. The edge-emitting laser planar packaging structure according to claim 1, characterized in that The N surface of the laser chip and the conductive substrate II of the negative substrate are electrically connected through conductive glue.

9. The method for manufacturing the edge-emitting laser planar package structure according to any one of claims 1 to 8, comprising the steps of: S1. Prepare the positive substrate and fix the insulating component A on the upper edge of the conductive substrate I by bonding with non-conductive adhesive; S2. Prepare the negative substrate and fix the insulating component B on the upper edge of the conductive substrate II by bonding with a non-conductive adhesive; S3, COS preparation, bonding the laser chip to the heat sink through gold-tin solder to form a COS, with the N side of the laser chip facing upward, and the heat sink can achieve upper and lower electrical conduction; S4, COS bonding, bonding the COS to the conductive substrate I of the positive substrate through conductive silver paste; S5. Packaging: Apply glue on the end face of the insulating component A of the positive substrate or apply glue on the end face of the insulating component B of the negative substrate, apply conductive silver paste on the N side of the laser chip, turn the negative substrate over, make the end face of the insulating component A and the end face of the insulating component B butt against each other, complete the buckling of the negative substrate and the positive substrate, and then bake to solidify the adhesive material; preferably, the baking temperature is 145-155°C, and the baking time is 60-90 minutes; preferably, the non-conductive glue is selected from epoxy glue or polyurethane glue.

10. Application of the edge-emitting laser planar packaging structure according to any one of claims 1 to 8, for manufacturing an edge-emitting laser module with adjustable light emission direction; preferably, except for the side in the light emission direction of the laser chip, each side surface or surface of the conductive substrate I and the conductive substrate II of the positive and negative substrates of the edge-emitting laser planar packaging structure can be used as a welding surface to achieve laser emission in different directions.

Images