Packaging structure of multiple laser chips

Abstract

The utility model relates to a packaging structure of multiple laser chips, comprising a copper sheet and a circuit extension board, the circuit extension board comprises a substrate layer, a copper foil conductive strip, a solder mask layer and a through groove, the circuit extension board comprises the substrate layer, the copper foil conductive strip and the solder mask layer from bottom to top, and the through grooves are positioned on the bottom surface of the substrate layer and are positioned below the corresponding copper foil conductive strips. According to the packaging structure of the multiple laser chips, the copper sheets and the chip bonding pads are arranged, the edge-emitting laser chips are installed at the tops of the copper sheets, the copper sheets can be used for effective heat conduction, meanwhile, the multiple chips can serve as coplanar electrodes, the routing cost is reduced, meanwhile, the circuit extension boards and the copper foil conductive strips with the same number as the chip bonding pads are arranged, and the packaging structure is convenient to use. The packaging structure can shorten the routing thread, meets the heat dissipation requirement of the low-power multi-laser chip while being low in cost, has certain local high temperature resistance, is more stable in device performance, and is convenient to popularize and apply.

Description

Technical Field

[0001] This utility model relates to laser chip packaging, specifically a packaging structure for multiple laser chips. Background Technology

[0002] Multi-laser chip packaging refers to the integration and packaging of multiple laser chip units. Its purpose is to integrate the wavelengths of different light-emitting chips together, such as in a tri-color laser, where laser chips emitting red, green, and blue light are integrated and packaged together. This technology can be applied to display devices such as projectors and laser TVs to achieve higher color performance and screen brightness, resulting in significant market demand.

[0003] Existing multi-chip packaging primarily integrates high-power lasers, with relatively less integration for low-power lasers. High-power laser chips generate significant heat, demanding high heat dissipation and thermal conductivity from the packaging, thus increasing material costs to meet performance requirements. However, for low-power laser chips, directly adopting the packaging methods of high-power lasers offers good performance but high packaging costs. While directly bonding the laser chip to the PCB board using an LED approach reduces packaging costs, it results in poor thermal conductivity, the PCB board cannot meet the heat dissipation requirements of low-power lasers, and device stability is compromised. Utility Model Content

[0004] This utility model provides the following technical solution: a packaging structure for a multi-laser chip, including a copper sheet and a circuit extension board. The circuit extension board includes a substrate layer, a copper foil conductive strip, a solder resist layer, and a through slot. The circuit extension board consists of a substrate layer, a copper foil conductive strip, and a solder resist layer from bottom to top. The through slot is located on the bottom surface of the substrate layer and below the corresponding copper foil conductive strip.

[0005] The top of the copper sheet is provided with at least one chip pad, and a laser chip is fixedly installed on the top of each of the multiple chip pads. A conductive wire extending to the corresponding copper foil conductive strip is fixedly installed on the top of each of the multiple laser chips.

[0006] Furthermore, the number of copper foil conductive strips, through slots, and chip pads is the same, which facilitates the installation and circuit connection of multiple chips. The corresponding copper foil conductive strips and through slots have the same shape, which can add a barrier layer between the copper foil conductive strips and the copper sheets, improving the ability to resist the substrate layer burn-through caused by local high temperature, which could lead to the copper foil conductive strips being open-circuited or directly contacting the copper sheets and short-circuiting.

[0007] Furthermore, each of the chip pads is provided with conductive wire pads and external wiring pads. The conductive wire pads are all located at the end closer to the laser chip, and the external wiring pads are all located at the end farther away from the laser chip. This can effectively shorten the wire bonding thread and improve the wire bonding yield. The solder mask layer is printed with connection guide lines connecting the corresponding conductive wire pads and external wiring pads, providing identification for easy identification.

[0008] Furthermore, the copper sheet and the circuit extension board are connected by pressing or bonding. The substrate layer of the circuit extension board is an insulating layer that blocks the copper sheet from the copper foil conductive strip. An external wiring solder joint is provided at the end of the top surface of the copper sheet away from the chip pad.

[0009] Furthermore, the middle part of the circuit extension board near the chip pad is missing to protect the two sides of the chip after installation.

[0010] Compared with the prior art, this utility model provides a packaging structure for multiple laser chips, which has the following advantages:

[0011] The packaging structure of this multi-laser chip, by setting up a copper sheet and chip pads, mounts the edge-emitting laser chip on top of the copper sheet. This not only allows the copper sheet to effectively conduct heat but also provides multiple chips as coplanar electrodes, reducing wire bonding costs. At the same time, the inclusion of a circuit extension board and copper foil conductive strips with the same number as the chip pads shortens the wire bonding process. This facilitates external control of individual or multiple chips to illuminate simultaneously, making it easy to adapt to different application requirements. This packaging structure meets the heat dissipation requirements of low-power multi-laser chips at low cost and has a certain degree of resistance to localized high temperatures, resulting in more stable device performance and facilitating its promotion and application. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the structure of this utility model;

[0013] Figure 2 This is a top view of the structure of this utility model;

[0014] Figure 3 This is a schematic diagram of the bottom surface of the circuit extension board of this utility model.

[0015] In the diagram: 1. Copper sheet, 2. Circuit extension board, 21. Substrate layer, 22. Copper foil conductive strip, 23. Solder resist layer, 24. Through groove, 3. Chip pad, 4. Laser chip, 5. Conductive wire. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] Please see Figure 1-3 A packaging structure for a multi-laser chip includes a copper sheet 1 and a circuit extension board 2. The circuit extension board 2 includes a substrate layer 21, a copper foil conductive strip 22, a solder resist layer 23, and a through slot 24. The circuit extension board 2 consists of a substrate layer 21, a copper foil conductive strip 22, and a solder resist layer 23 from bottom to top. The through slot 24 is located on the bottom surface of the substrate layer 21 and below the corresponding copper foil conductive strip 22.

[0018] The top of the copper sheet 1 is provided with at least one chip pad 3, and a laser chip 4 is fixedly installed on the top of each of the multiple chip pads 3. A conductive wire 5 extending to the corresponding copper foil conductive strip 22 is fixedly installed on the top of each of the multiple laser chips 4.

[0019] In this embodiment, the number of copper foil conductive strips 22, through slots 24 and chip pads 3 are the same, which facilitates the installation and circuit connection of multiple chips. Correspondingly, the copper foil conductive strips 22 and through slots 24 have the same shape, which can add a barrier layer between the copper foil conductive strips 22 and the copper sheet 1, and improve the ability to resist the copper foil conductive strips 22 from being broken or short-circuited due to the substrate layer 21 being burned through by local high temperature.

[0020] In this embodiment, each chip pad 3 is provided with a conductive wire pad and an external wiring pad. The conductive wire pads are all located at the end close to the laser chip 4, and the external wiring pads are all located at the end far from the laser chip 4. This can effectively shorten the wire bonding thread and improve the wire bonding yield. The solder mask layer 23 is printed with connection guide lines connecting the corresponding conductive wire pads and external wiring pads, providing markings for easy identification.

[0021] In this embodiment, the copper sheet 1 and the circuit extension board 2 are connected by pressing or bonding. The substrate layer 21 of the circuit extension board 2 is an insulating layer that blocks the copper sheet 1 from the copper foil conductive strip 22. An external wiring solder joint is provided at the end of the top surface of the copper sheet 1 away from the chip pad 3.

[0022] In this embodiment, the middle part of the circuit extension board 2 near the chip pad 3 is missing to protect the two sides of the chip after installation.

[0023] The beneficial effects of the above embodiments are as follows:

[0024] The packaging structure of this multi-laser chip, by setting a copper sheet 1 and chip pads 3, mounts the edge-emitting laser chip on top of the copper sheet 1. This not only allows the copper sheet to effectively conduct heat but also provides multiple chips as coplanar electrodes, reducing wire bonding costs. At the same time, the circuit extension board 2 and the same number of copper foil conductive strips 22 as the chip pads 3 can shorten the wire bonding process and facilitate the chip to be controlled externally to light up one chip or multiple chips simultaneously, making it easy to adapt to different application requirements. This packaging structure meets the heat dissipation requirements of low-power multi-laser chips at low cost and has a certain resistance to local high temperature, resulting in more stable device performance and facilitating promotion and application.

[0025] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-laser chip package structure comprising a copper sheet (1) and a circuit extension plate (2), characterized in that: The circuit extension plate (2) comprises a substrate layer (21), a copper foil conductive strip (22), a solder resist layer (23) and a through slot (24), the circuit extension plate (2) is from bottom to top the substrate layer (21), the copper foil conductive strip (22) and the solder resist layer (23), the through slot (24) is located at the bottom surface of the substrate layer (21) and below the corresponding copper foil conductive strip (22); The top of the copper sheet (1) is provided with a plurality of chip pads (3), the top of each of the plurality of chip pads (3) is fixedly installed with a laser chip (4), and the top of each of the plurality of laser chips (4) is fixedly installed with a conductive wire (5) extending to the corresponding copper foil conductive strip (22).

2. The multi-laser chip package structure of claim 1, wherein: The number of the copper foil conductive strip (22), the through slot (24) and the chip pad (3) is the same, and the corresponding copper foil conductive strip (22) and the through slot (24) are the same in shape.

3. The multi-laser chip package structure of claim 1, wherein: The chip pad (3) is provided with a conductive wire pad and an external wire pad, the conductive wire pad is located at one end close to the laser chip (4), the external wire pad is located at one end away from the laser chip (4), and the solder resist layer (23) is printed with a connection guide line connecting between the corresponding conductive wire pad and the external wire pad.

4. The multi-laser chip package structure of claim 1, wherein: The connection mode of the copper sheet (1) and the circuit extension plate (2) is pressing or bonding, the substrate layer (21) of the circuit extension plate (2) is an insulating plate layer, and the copper sheet (1) is provided with an external wire welding point at one end away from the chip pad (3) on the top surface.

5. The multi-laser chip package structure of claim 1, wherein: The middle part of the circuit extension plate (2) close to one end of the chip pad (3) is missing.

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